Upon Janet Julian replacing Pamela Sue Martin in the second half of season two, Nancy Drew was only seen teaming up with the Hardy Boys, and never any solo stories. ABC however, did continue to air Martin's episodes over rerun periods. For the third season, Nancy Drew was completely eliminated from the series, which was re-titled simply "Hardy Boys."
Already over twenty-one when she was cast as teenage Nancy Drew, Pamela Sue Martin became disappointed with the more juvenile aspects of the role.
Not happy with her role, Pamela Sue Martin requested a release from her contract during the second season. The network and the producers refused. Playboy had been sending her offers to pose for their magazine but she kept turning them down. After learning she couldn't leave the show, she accepted Playboy's offer, knowing it would anger the producers. She also wanted to show the world she was no longer a little girl after playing so many family friendly roles. Martin told the magazine she would only pose semi-nude, but on the day of the photoshoot, she was so relaxed and enjoying it, she ended up posing fully nude. When the magazine came out in July 1978 with her on the cover and the headline "Nancy Drew Uncovered," the network fired her.
Merchandising for the series included action figures (a guitar accessory for the Joe Hardy figure included a "secret panel" to decode messages), and a series of puzzle books, also sold as a gift set.
Shaun Cassidy, younger half-brother of musician David Cassidy, was an up-and-coming teen pop star when he was cast in the series. His musical interests were worked into storylines.