In the level "Dance With the Devil" is a kitchen crate in the freezer room of the Hell party. Its description reads, "Allan please add details", presumably accidentally left in by game developer Allan Hansen.

In the mission "Till Death Do Us Part", there is a small coin near the water at the front of the mansion. If the player shoots it, the group of guests which were previously fighting each other will lose their clothes and run towards Agent 47, clapping their hands. After some time, they will resume fighting, though they will still only be wearing underwear.

A Hitman website is visible on a computer screen near the start of the mission "A Dance with the Devil".

In the mission Amendment XXV, in the wing in which Morris initially can be found, is a hall with a fireplace that isn't lit. Throwing a lady's briefcase (from the lady that goes for a smoke at the beginning of the mission) into the fire three times correctly, causes the marines to all form a line and start dancing the can-can. A marine suit is also needed for this.

The song "Apocalypse" in Hitman: Blood Money's soundtrack is a re-worked version of a song that composer Jesper Kyd used in two previous games he worked on. The song was first written for the Sega Genesis game Red Zone in 1994 and released under the name "Spinner", was then re-worked for the PC and Sega Saturn game Amok in 1996 under the name "Wastelands", before being remade once more for Hitman: Blood Money in 2006 under the name "Apocalypse".