In this study, egg quality determination of common dentex (Dentex dentex) was investigated by using egg, yolk and oil globule diameter from the first division to the hatching, during natural and photoperiodic manipulation of spawning time. In the viable, floating eggs, the minimal and maximal diameter of the egg, yolk and oil globule were measured. Based on these measurements several parameters were calculated describing the shape of the egg, yolk and oil globule and the size relationship between these compartments. Hatching rate was calculated as 92% in natural spawning time (NST) and 61% photoperiodic manipulation of spawning time (PMST). Also, average egg diameter was measured as 0.949 +/- 0.038 mm in NST and 0.911 +/- 0.014 mm in PMST. In NST, egg diameter and yolk diameter of the eggs were significantly bigger than eggs in PMST (P<0.05). The morphometric parameters of oil globule could be accepted as an indicator for description of quality criteria of eggs.