•
Dr. Howard Sheinfeld (
Elliott Gould): A twice-divorced otolaryngologist (his wives were named Sheila and Phyllis) and father of two (David and Jenny, his children with Sheila), who—in order to keep up his alimony payments to said ex-wives—works long hours at Clark Street Hospital's emergency room. Despite his joking nature and his constant womanizing, he is a compassionate and well-respected doctor. •
Dr. Eve Sheridan (
Marcia Strassman in the pilot;
Mary McDonnell thereafter): The head doctor in the ER. Born in a medical family (her father was also a doctor), she takes her job very seriously. She tends to come down hard on Howard for his constant joking and his lack of medical protocol, but she is also concerned for him because he works such long hours in the emergency room with absolutely little or nothing to show for it (since whatever money he makes goes to his ex-wives for alimony). At times she is very strict with her staff, almost to the point of angering them, but she truly does mean well and is a fine doctor. Eventually, Eve was able to let her hair down with the staff and was considered their friend. •
Nurse Joan Thor (
Conchata Ferrell): The head nurse in the ER. She is close friends with Howard and, like Eve, worries about him. She has a tough exterior, but a heart of gold. She is often seen talking on the phone to her husband, Bud Thor. Her nephew, Mark "Ace" Kolmar, who is an EMT, was hired to work in the ER as a technician. Thor is diagnosed with
Hodgkin's disease late in the series' run. •
Nurse Julie Williams (
Lynne Moody): Joan's industrious and efficient assistant. She is kind and good natured. Her aunt and uncle are
George and
Louise Jefferson from
The Jeffersons. She shares an apartment with receptionist Maria Amardo, to help save money. •
Maria Amardo (
Shuko Akune): The ER's Filipino-American receptionist. Known for her strict enforcement of the white line rule (her catch-phrase, "Stay back of the white line!!"). She dates Officer Fred Burdock, the beat cop, but is afraid of marriage due to her interracial parents' divorce. Shares an apartment with nurse Julie Williams, to help both of them save money. •
Nurse Cory Smith (
Corinne Bohrer): A pediatric nurse who comes to help in the ER when it gets too busy. Is in love with Howard, who only sees her as a colleague, due to his being burned by his two divorces. •
Officer Fred Burdock (
Bruce A. Young): The beat cop in the area of Chicago where Clark Street Hospital is located. Dates Maria Amardo, of whom he is insanely jealous, although marriage isn't in the cards due to Maria's fear of divorce. Officer Burdock is also close friends with the rest of the ER staff. Diagnosed with high blood pressure late in the series' run. He did go out once, with Maria's roommate, Julie. A more complete cast list follows: ==Reception==