A urinary incontinence prevention instrument for males includes: an annular part made by annularly forming a portion of a belt-like component； a convex part for pressing the urethra, convex parts attached to the inner circumference surface side of the annular part； and an adjusting mechanism for adjusting the diameter of the annular part. The instrument includes a lodge-proof prevention component having a hole for passing the belt-like component. The lodge-proof prevention component, positioned between the penis and the adjustment mechanism, prevents the skin of the penis from being lodged in the adjustment mechanism.
