Actress Kathy Steinberg had almost finished recording all her lines of dialog as Sally when the producers received a phone call from Steinberg's mother informing them that one of Kathy's teeth was loose. Fearing that a sudden lisp would ruin the continuity dialogue, the producers rushed the young actress into the studio to finish recording her lines. Just as Steinberg was speaking her last line, the tooth came flying out of her mouth.
The songs that Schroeder plays for Snoopy include World War One songs 'It's a Long Way to Tipperary', 'There's a Long, Long Trail' and 'Roses of Picardy' and 'Pack Up Your Troubles In Your Old Kit Bag.'
When writing a letter to the Great Pumpkin, Linus states, "You must get discouraged because more people believe in Santa Claus than in you. Well, let's face it; Santa Claus has had more publicity, but being #2, perhaps you try harder." This is a reference to an advertising slogan for Avis Rent-a-Car that was well known in the 1960s.