Over a four year period, gonad index, examination of gonad tubules, and histology were used to study the reproduction in the sea cucumber Actinopyga mauritiana. This species reproduced annually during the warmer months of the year in Solomon Islands. This annual reproductive cycle progressed through five maturity stages: recovery, growing, mature, partly-spawned and spent. The recovery stage (March–May) was marked by initiation of gametogenesis and coincided with decreasing day length. The growing stage (June–September) was characterized by development of gametes through to the mature stage (October–December). Spawning occurred October through December and coincided with increased water temperature and day length. Spent gonads (January–March) contained a few unspawned gametes or completely lacked gametes. Although A. mauritiana had annual reproduction, individuals lacking or having indeterminate gonads were present year-round. Macroscopic examination of gonad tubules after biopsy provides a practical tool for assessing maturity condition of broodstock in the field during the reproductive season.