An abdominal exercise machine includes a U-shaped base, a head member, two first mounting members, and two handles. The base includes a main portion, and two arm portions extending from opposite ends of the main portion. The head member is mounted to main portion of the base. The first mounting members are mounted to corresponding arm portions of the base. A plurality of locating portions is formed on each of the first mounting members. Each of the mounting members has an arc-shaped edge. The handles are rotatably mounted to the corresponding mounting members. The handles are selectively mounted to the location portions of the corresponding first mounting members.