A composite writing implement is capable of being used as a ball-point pen, a mechanical pencil or a stylus pen. The composite writing implement includes a barrel, a pencil lead feeder unit axially slidably placed in a front part of the barrel, a ballpoint refill unit disposed behind and coaxially with the pencil lead feeder unit in a back part of the barrel and including a ballpoint refill case and a ballpoint refill fixedly held in the ballpoint refill case, a rotary cam operatively connecting the ballpoint refill case and the pencil lead feeder unit, and a cap put on the ballpoint refill case so as to cover the ballpoint tip of the ballpoint refill, provided with a stylus tip, capable of being used as a stylus and means for turning the rotary cam through the ballpoint refill case to make the pencil lead feeder feed a lead.