This study presents the effects of age on the accessory glands of male Anopheles albimanus. The paired oval glands have an outer muscular layer and an inner layer of columnar secretory cells. Male pupae have uniformly long columnar cells and contain only traces of male accessory gland substance (MAGS). In newly emerged males, the posterior section of the gland has short columnar cells that produce an opaque, white MAGS consisting of one type of secretory granules. The anterior section has long columnar cells that produce yellow as well as white MAGS. In 84-h-old males, the columnar cells are short throughout the gland and the glands are replete with both forms of MAGS. The amount of MAGS may control secretory activity of the columnar cells by a feedback mechanism.