[Issue] To provide a guidewire insertion aid which is very easy to operate because a lubricated guidewire can be easily fed out.[Means of Resolution] A guidewire insertion aid 11 according to the present invention is used for feeding out a guidewire 1 inserted in a housing 2 in order to insert said guidewire into the lumen of a piece of medical equipment. The insertion aid 11 comprises: a main body 21, a housing support part 22 and a guidewire support part 26. A sliding contact part 28 is disposed between the housing support part 22 and the guidewire support part 26. The sliding contact part 28 extends in the lengthwise direction of the main body and has a sliding contact surface 28 for the guidewire 1. A feed-out member 51 is provided on the main body 21 and has a water-retentive water-retention member 52. The feed-out member 51 is disposed with the water-retention member 52 side thereof facing towards the sliding contact surface 29. The feed-out member 51 can be displaced while the guidewire 1 is held between said feed-out member and the sliding contact part 28.