There are little published data on the ecology of the capped langur (Presbytis pileatus), so a study of this species was undertaken at Madhupur National Park, Bangladesh, from December 1977 to July 1978. The langurs spend 32% of their 709-min day feeding, 49% in sitting and resting, and 19% moving, playing and grooming. Feeding occurs in the early morning and late afternoon, and there is a peak of resting in the middle of the day. Leaves form the major part of the diet (61 %), with flowers, fruits, and seeds next in importance (30%). On average, groups move about 450 m each day.