Dates:

• - The episode, Humbug originally aired 3/31/95 - the day before April Fool's Day.
• - Syzygy first aired on January 12, 1996. That date actually was during a syzygy of Mars, Mercury, and Uranus (just like in the episode)
• - Episode 4X20, Small Potatoes, aired on 4/20/97 (he, he, he)

The X-Files pulls a Law and Order:

• - The same dog that appears in the episode Ice also appears in the episode Duane Barry.
• - Chris Owens portrays young Cancerman in Musings of a Cigarette Smoking Man and Demons, The Great Mutato in Post-Modern Prometheus and also the recurring role as Special Agent Jeffrey Spender.
• - In the episode, Genderbender the character "Michael" played by Nick Lea, later to be seen as Alex Krycek.
• - In the episode, Die Hand Die Verletzt, Sheriff John Oakes, played by Larry Musser, is also later Sheriff Jack Bonsaint in the episode Chinga.
• - In Død Kälm, the bartender, Barry (Bear) Hortin, is also the bartender in the epsiode Never Again.
• - In F. Emasculata, the production assistant, Angelo Vacco, plays gas station attendant Angelo Garza, a part Chris Carter wrote especially for him. Vacco was also 's other appearances, check the in-jokes for a door man in Talitha Cumi, Kevin in Milagro, and a bartender in Improbable.

Family members in the show:

• - Mulder and Scully's names: Mulder is Chris Carter's mother's maiden name. Scully is named after sports announcer Vin Scully. The name Fox belonged to one of Chris Carter's childhood friends. Chris Carter's father's name is William, and it is also David Duchovny's middle name (Scully's father's name was William, Mulder's father's name was William, one of Scully's brothers is named William and Mulder's middle name is William). Chris Carter's mother's name is Catherine (Scully's middle name is Katherine).
• - 'I made this' - The words spoken over the Ten Thirteen company name are spoken by Nathan Couturier, son of the supervising sound editor, Thierry Couturier.
• - Zoe Anderson, Gillian Anderson's younger sister, played the teenage Dana Scully in A Christmas Carol.
• - The name of the episode, Piper Maru is also the name of Gillian Anderson's daughter, Piper Maru Anderson.
• - The black and white dog often seen in the show (see above), is the father of David Duchovny's dog, Blue.

Episode Titles and Tag Lines

• - Die Hand Die Verletzt: German for "The hand that wounds."
• - Død Kälm: Norwegian for "dead calm."
• - Oubliette: a medieval dungeon having a trap door in the ceiling as its only means of entry or exit; from the French word "oublier," to forget.
• - Nisei: a Japanese word for a child born in America or Canada to Japanese parents (who were born in Japan); it literally means "second generation."
• - Talitha Cumi: Aramaic for "little girl rise." The phrase is used in the Bible (Mark 5:41), spoken by Jesus when he raises the daughter of a Jewish leader from the dead.
• - Memento Mori: Latin for "a reminder of death."
• - Kitsunegari: Japanese for "fox hunt"; "Kitsune" means "fox", and "Gari" means "hunting."
• - The Sixth Extinction II: Amor Fati: Latin for "Love of Fate."
• - Orison: the definition of "Orison" is "a prayer."
• - éí 'aaníígÓÓ 'áhoot'é: Navaho for "Far away from here, the Truth is" from Anasazi
• - Die Wahrheit Ist Irgendwo Da Draußen: German for "The Truth is Out There Somewhere" from Triangle
• - Amor Fati: Latin for "Love of Fate" from The Sixth Extinction II: Amor Fati
• - erehT tuO si hturT ehT: The Truth is Out There backwards from 4-D
• - Dio Ti Ama: Italian for "God Loves You" from Improbable

Extra things

• - In the episode Blood, the nurse buzzing on the door buzzes the word 'Kill' in Morse code.
• - Krycek (as in Alex Krycek), can be likened to Krysa which is the word for 'rat' in Russian and Czech.
• - Melinda McGraw (the actress who plays Melissa Scully) worked on "The Commish" with writers Glen Morgan and James Wong and the part of Melissa was written specifically for her.
• - Gillian Anderson actually ate the bug in the scene where Scully does the magic trick in Humbug.
• - Show creator, Chris Carter, makes a cameo appearance (and his acting debut) as one of Scully's interrogators in Skinner's office in the episode Anasazi.
• - Scully's tattoo, called an ouroboros, is a mythical serpent biting it's own tail. It is a symbol of the unending cycle of the universe and a cycle of destruction and re-creation.
• - In the episode The Unnatural, the baseball announcer on the television as Scully is on her way to Mulder's office is Vin Scully, the man after whom Chris Carter named Agent Scully.