Dave Malucci first appears as a second-year resident. He often breaks protocol to get things done and appears to lack warmth towards patients, but is occasionally shown to be both sensitive and insightful, particularly where younger patients are involved. In "Last Rites," Malucci and John Carter steal medical gear from an ambulance to help some construction workers injured at a site; later, Kerry Weaver reprimands them for violating emergency protocols and Carter comes away with a negative view of Malucci that he never really changes his mind about. Malucci attended medical school in Grenada, and in "Great Expectations," he uses his knowledge of the Caribbean to accurately diagnose a patient with a rare disease called Jamaican Vomiting Sickness because he recognized the symptoms from eating the area's akee fruit. In "Such Sweet Sorrow," Malucci allows Abby Lockhart to discharge a female patient without examining her personally. The patient later suffers an internal injury and nearly dies. After performing surgery to save the patient, Elizabeth Corday bluntly tells Malucci the staff considers him a sloppy, lazy physician and that " think you're much of a doctor." Although his incompetence and abrasiveness were the source of several dramatic events, he was most often used for comic relief due to his offbeat personality and tendency to get pranked, injured, or end up doing odd things like eating cereal out of an Emesis basin. He and Jing-Mei "Deb" Chen had a somewhat-adversarial relationship that also hinted at possible signs of attraction between the two; Dave appeared visibly flustered when Deb walked into County's front desk to pick up files wearing a "nice" dress while he was trying to flirt with Abby. This got shunted aside once Dave found other staff members to annoy after his repeated flirtations were efficiently shut down and Deb entered into a relationship with ICU Nurse Frank Bacon.
Season 7
Malucci continues to clash with other staff members in Season 7. When Mark Greene discounts his view that a teenage patient is being mistreated by his father, a visibly hurt Malucci makes a snide remark about Greene's brain tumor, leading to friction between the two. In "The Visit," Peter Benton's nephew Jesse dies in the ER from gunshot wounds, and Malucci's callous, gang-related remarks provoke Benton into physically attacking him. His attraction to Dr. Chen disappears without any explanation and no signs of it ever resurface; their relationship is shown to be adversarial in a late season episode when an angry patient refuses to let Malucci examine her; when asked to take over, Chen lashes out at Malucci and refuses to help. The patient, a homeless former TV show host later recognized by Kerry Weaver, then sprays Malucci with Mace.
Season 8
In "The Longer You Stay", Chen and Malucci attempt to treat a patient without compiling a complete medical history and fail to recognize his illness as Marfan syndrome, which Carter correctly diagnoses immediately after seeing the patient's chest X-ray, but too late to do anything. Malucci mistakenly assumes the patient is a drug user, and the procedure he and Chen perform proves to be fatal. Kerry Weaver, the on-duty attending physician during this incident, could not be reached because she had gone across the street to Doc Magoos and left her pager in the restroom. When she returns and learns of Chen and Malucci's procedure, which required her authorization to be performed, she became enraged and tells Malucci that "in a perfect world, Dr. Malucci, I would never subject any patients to your care." Chen is ultimately forced to resign over the incident, though she later appeals the decision and returns. In "Blood, Sugar, Sex, Magic", Malucci is caught having sex with a paramedic in an ambulance, giving a still-angry Weaver an excuse to recommend his dismissal. Mark Greene attempts to convince Weaver that she cannot fire Malucci simply because she doesn't tolerate him, since by that criterion "You'd have to fire all of us!". Weaver cites several letters of reprimand and two failed rotations on file, promising that even if the hospital chooses not to terminate Malucci, she will ensure he never works in the ER again. In a last-ditch effort to save his job, Malucci reveals to Weaver that he "has a kid to support." Weaver wavers for a minute, but then repeats that he is fired. In retaliation, he bitterly tells Weaver that the only reason she wants to be in charge of the ER is because she has nothing and no one else in her life. He leaves after calling her a "Nazi dyke". Malucci appears for the final time in "Never Say Never" when Weaver enters the doctor's lounge as he is cleaning out his locker. While removing his name tag, he and Weaver have a moment of mutual enmity. He then leaves the lounge and County, never to be seen again. Malucci was the first of four characters to leave in season 8. He is mentioned in the episode "Brothers and Sisters", when Dr. Carter tells young resident Michael Gallant that Malucci was reckless and "killed a patient". This would be the last time Malucci would be acknowledged by any of the characters on the show.
Season 15
During the 15th and final season of ER, at the end of the episode "The Book of Abby", long-serving nurse Haleh Adams shows the departing Abby Lockhart a closet wall where all the past doctors and employees have put their locker name tags. Amongst them, the tag "Malucci" can be seen.
