An instrument (10) for extracting a pin from a substrate, such as a bone mass, which comprises a first lever arm (20) with a body part (24) having a channel in which a free end of a pin can be received, a second lever arm (22) which can pivot relative to the first lever arm, a gripping member within the body part by which the pin can be gripped to retain the pin in the channel, and a terminating member (28) mounted on the body part having an end face (80) and two side walls (44, 46) which extend along opposite sides of the body part. The terminating member has a slot (60) provided in a portion of the end face and which extends along a portion of at least one of the two side walls configured to guide the free end of the pin into the instrument prior to being received into the channel. The provision of a slot on the side as well as the front enables a user, such as a surgeon, to manoeuvre the pin to be extracted into the channel either through the front of the extraction instrument or at the side. This enhances the flexibility of the instrument and means that the user is less prone to misaligning the pin within the extraction instrument. The provision of the slot passing along at least a portion of the side of the instrument also provides tactile feedback to the user which enhances the ease of use of the instrument to remove pins.