There are provided a balloon catheter by which a drug can be effectively delivered to living body tissue and the deliverability can be controlled and a manufacturing method thereof, and a treatment method. Disclosed is a balloon catheter (10) provided on an outer surface of a balloon (30) with a plurality of elongate bodies (42) which are crystals of a water-insoluble drug extending while having independent long axes. The balloon catheter (10) has a base layer (41) including a water-soluble low-molecular compound disposed in a layer form on the outer surface of the balloon (30), and at least part of the elongate bodies (42) is located in the inside of the base layer (41).