Star Trek: The Next Generation
Muldaur is known for playing "dignified, sophisticated characters". Gene Roddenberry was already familiar with Muldaur from her second-season appearance in the Star Trek episode, "Return to Tomorrow", and later in a third-season appearance in "Is There in Truth No Beauty?". He subsequently cast her in his 1973 TV movie Planet Earth. Consequently, for the second season of Star Trek: The Next Generation, Roddenberry chose her specifically to replace the outgoing Gates McFadden (who was let go at the insistence of the show's first-season producer Maurice Hurley). Muldaur was cast to play the role of Dr. Pulaski, the new chief medical officer. "We needed someone with a little more of an edge," Rick Berman explained of the choice. "Kate's a strong, confident woman with an edge who can hold her own with Captain Picard. Their relationship is not all that unlike the one between Kirk and McCoy ... although from the onset we had no intention of trying to duplicate the original team."
Muldaur said after her casting
I hadn't kept in touch with Gene over the years. I'd only done a pilot of his, Planet Earth, in 1974, so this call was totally out of the blue. I love being back in Star Trek. It's a challenge, but a healthy challenge. I find so much TV depressing—even the sitcoms. The chances of shows working and being funny or meaningful are very slim, but this show is very exciting. It has such an uplifting view of humanity in the 24th century. They want the crafty old doctor, so basically I'm a woman Dr. McCoy.
Of Pulaski's willingness to stand up to the captain, Muldaur said
We've been in a fairly stormy relationship due to two very strong personalities, but we end up admiring each other. I'm also giving Brent Spiner (as the android, Data) a very hard time, treating him as a total machine, because that's how I see him, a machine that I can't treat and I don't deal with. But I'm also beginning to see the wonderful android that he is.
Some television critics praised Muldaur's performance, with one noting her "wry, no-nonsense warmth that plays nicely off of some of the icier regulars". The addition of Muldaur, along with Whoopi Goldberg, also served to redress the absence of women from the principal cast, as the departure of McFadden and Denise Crosby had left only Marina Sirtis, a rapid attrition of women that recalled the imbalance of the original Star Trek series.
Ultimately, Muldaur found working on the syndicated show an "unhappy" experience, saying, "The imagination and joy wasn't there". "Everybody was out for themselves. I don't think they were happy to have me there." "It wasn't what I hoped it would be. I thought it would be wonderfully inventive and wonderfully creative, and I found it was not any of those things, but it did give me Trekkies. I love Trekkies. I find them very dear."
The character also proved unpopular with some fans, who among other things found her treatment of the android character Data to be mean-spirited. Muldaur left the series after a season. Show representatives denied that she had been fired, saying, "Technically, she's just not returning", while other sources said that her option had not been renewed. Roddenberry described Muldaur as "a most talented actress" and said that the decision "to let her go was made solely because the hoped-for chemistry between her and the rest of the starship cast did not develop." Berman added, "The thought of bringing Gates back was a good idea to us. The feeling was that we had perhaps made a mistake, and the best way to remedy it was to bring her back." The "revolving door" and the limited opportunities for female crew led critics to suggest that the mostly male series still had a problem featuring women.