After this episode originally aired, children all over America sent valentines to Charlie Brown out of sympathy. (See also C'est la grosse citrouille, Charlie Brown (1966))
As Schroeder passes out the valentines, one of the names he calls out is Joanne Lansing. Joanne Lansing is the ink and paint supervisor for this and many of the other Peanuts specials.
All the hand puppets Snoopy holds up during the end credits are caricatures of the crew members listed when they appear
As of 2020, Valentine's Day is the only other holiday besides Christmas that has more than one Peanuts special devoted to it. A second New Years special debuted in 2021.
Among the names that Schroeder calls out while passing out Valentines are the names of Charles M. Schulz's own children.