This was the first US Western television show to have all its episodes filmed in color.
Both Robert Blake and Robert Fuller were considered for the role of Little Joe Cartwright, but were both lost to Michael Landon. This was because Executive Producer David Dortort had mixed feelings about the new, unfamiliar actor auditioning for the part, thinking Landon was way too young to play the role. With the encouragement of David's wife, who picked up a publicity still of Landon, her husband changed his mind, and bestowed Landon the role.
During the first season of the show, the guest stars were paid far more than the stars of the show because the producers didn't think that the stars were well-known enough to pull in viewers.
Saturday night ratings were dismal and Bonanza was soon targeted for cancellation. Given one last chance, it was moved to Sunday nights at 9:00 p.m. The new time slot caused the series to soar, and it eventually reached number one by the mid-'60s.
Anthony Lawrence didn't write authentic Western scripts so he focused on writing about relationships and character (as he did in Bonanza: Dark Star and Bonanza: The Last Viking, for example). One day, producer David Dortort told Lawrence he wanted to do a story on each of Ben's wives, and the screenwriter replied, "Let me do it, I can kill off at least two of them!" Lawrence thought he would get thrown off the set for saying this, and instead was given the task of becoming the writer who scripted the stories with Ben and his wives, all three of whom died (Bonanza: Elizabeth, My Love, Bonanza: Inger, My Love, Bonanza: Journey Remembered, and Bonanza: Marie, My Love).
The character 'Ben Cartwright' was ranked #2 in TV Guide's list of the "50 Greatest TV Dads of All Time" (20 June 2004 issue).
Most viewers have only heard the famous theme song by Jay Livingston and Ray Evans played as an instrumental. The theme song actually had lyrics and there is footage of the lead actors singing those lyrics. Lorne Greene, Dan Blocker and Michael Landon sang a lyric version of this famous instrumental theme for the pilot, but it never aired. Johnny Cash recorded his own version of the theme song.
From the third season on, the Cartwrights and nearly every other recurring character on the show wore the same clothing in almost every episode. This was done to cut the cost of re-filming action shots (such as riding clips in-between scenes), as previously-shot stock footage could be reused.
In 1968, Dan Blocker began wearing a toupee on the series as he was approaching forty and losing hair. He joined the ranks of his fellow co-stars Pernell Roberts and Lorne Greene, both of whom began the series with hairpieces (Greene wore his modest frontal piece in private life too, whereas Roberts preferred not wearing his, even to rehearsals/blocking). Michael Landon was the only original cast member who was wig-free throughout the series, as even Victor Sen Yung's Hop Sing wore an attached queue (ponytail).
During the filming of one episode, Lorne Greene was required to jump off a small ledge into a lake five feet below. Michael Landon later recalled that when Greene did the stunt, he jumped into the water feet first and went completely under, but his hair piece came off and floated on the surface of the lake. Landon and the rest of the crew watched to see what would happen. After a short while, Greene's hand shot up out of the water, grabbed the hairpiece, and pulled it down. Greene emerged from the lake, wearing his hairpiece slightly askew. He walked nonchalantly past the snickering crew, and went into his trailer without saying a word.
Dan Blocker owned a chain of restaurants called "Bonanza". They were steakhouses similar to the "Golden Corral" chain. When the ownership later changed, all of the restaurants were later renamed "Ponderosa".
When Dan Blocker died unexpectedly shortly before filming began for the final season, it was decided to have Hoss die too by having him killed in an accident. The opening episode, a two-hour special in which Little Joe marries only to see his bride die, was originally scripted to feature Hoss. This was the first time a TV series had incorporated an actor's death into the storyline by having his character die.