Provided are a balloon catheter capable of effectively delivering a drug to living body tissue and a manufacturing method thereof, and a treatment method. The balloon catheter 10 has a balloon 12 at a distal portion of a catheter shaft 11, and is provided on a surface of the balloon 12 with elongate bodies 33 which are crystals of a water-insoluble drug extending in a longitudinal direction. The surface of the balloon 12 is provided with crystal conjugates 38 formed of a plurality of elongate bodies 33 united to one another while being in a tilted state.
