Bodily-fluid-contacting medical tool, and biocompatible polymer

This bodily-fluid-contacting medical tool has a coating film provided to a bodily-fluid-contacting surface thereof. The coating film includes a block polymer provided with: an acrylic polymer block formed from an acrylic monomer having an average water/1-octanol distribution coefficient (LogP) in the range of 0-2 inclusive; and a polyethylene oxide block.