Disclosed is a guide for a flexible bone drill, including: a first body provided internally with a through channel; a second, internally hollow body, into which said first body can be inserted; said second body being provided with a through hole suitable to be placed in fluidic connection with the internal through channel of said first body; and said second body and said first body sliding relative to one another to vary the relative position of the hole with respect to said through channel. Other aspects are described and claimed.