Kaplan was executive producer of "ABC News Nightline" from 1984 to 1989, where he guided the late-night news program through a period of innovation and exclusive interviews. While at "Nightline" in March 1985, Kaplan produced the historic week-long series of broadcasts originating from Johannesburg, South Africa. In 1988, Kaplan was executive producer of "Nightline in the Holy Land", a critically acclaimed week-long series examining Arab–Israeli conflicts. At that time he was also responsible for an unprecedented four-hour "Nightline National Town Meeting" on AIDS, the most comprehensive coverage of the epidemic ever shown on network television.