Sarah's Diary is Sarah's own personal diary in which she records her own personal thoughts. She keeps the diary's existence a secret to everybody except for Jimmy. Its only appearance was in "For Your Ed Only." The diary's cover is plain white, has a pink teddy bear's face on it, and says "Sarah's Diary" in red (the dot on the "i" is replaced with a heart). The diary also has a lock and requires a key to open it (although Eddy was able to pick the lock with his hair). Inside the diary, it contains writings from Sarah about what happened on a certain day, her opinions, and her crush on Edd. A more unique thing in the diary is a cartoon of a poorly drawn Eddy walking and then being struck by lightning and getting hit by a brick.
During the episode, the diary got broken, torn up, and covered in drool stains due to Eddy keeping it hidden in his mouth temporarily. However, Sarah appears to have gotten a new diary as a replacement as shown when she is writing an entry at the end of the episode.
- A passage read by Eddy saying "Dear Diary, Double D is so cute. Last night I dreamed that he gave me a horsie."
- The Eddy cartoon.
- A smudged group of words which reads: "Dear diary today Jin (possibly Jimmy) an I-".
- Sarah's writing at the end of "For Your Ed Only": "Dear Diary, my brother and that stupid Eddy got what they deserved today. Double D looked so innocent, but you know what they say; give those cute ones an inch and they'll take a mile."