The age and growth parameters of grey triggerfish, Balistes capriscus from the Gulf of Gabès, southern Tunisia, Mediterranean Sea, were estimated from the first dorsal spine sections of 463 specimens (206 males and 257 females), whose fork length was between 139 and 427 mm and the total weight ranged from 90.04 to 1967.41 g. The monthly percentage of specimens having a terminal translucent zone has indicated that the growth zone is formed once a year, during the cold season (February). The von Bertalanffy growth equations were: FL = 420.7 [1 − e−0.233(t + 0.123)] and FL = 417.0 [1 − e−0.238(t + 0.074)], for males and females, respectively. The longevity estimated was 13 years old for both sexes. The instantaneous mortality rates were estimated to 0.23 for males and 0.24 for females. The weight–length relationships of the grey triggerfish were Wt = 21.510−3 LF3.046 and Wt = 41.010−3 LF2.835, for males and females, respectively.