Skipjack tuna, Katsuwonus pelamis (Linnaeus, 1758) is one of the most important species for Indonesian marine capture fisheries and is the third major species of capture fisheries in the world. This study aims to analyze the biometry of otolith (sagitta) of skipjack tuna caught with ‘soma pajeko' (mini purse-seine) around FADs in the Sulawesi Sea. A total of 96 individuals of skipjack tuna measuring total length (TL) ranged between 232 and 625 mm and the average of TL was 419.64 mm (SD = 112.78 mm) were successfully taken otolith without defects. The length of otolith (OL) of the skipjack tuna ranged between 2.693 and 5.269 mm with an average of OL was 3.435 mm (SD = 0.602 mm). For both the size and shape indices of the otolith, there were no significant difference between the left and right otoliths for otolith length (OL), otolith perimeter (OP), Form-Factor (FF) and Roundness (Rnd), but asymmetric influences were very significance for otolith width (OW), otolith area (OA), Circularity (Cir), Rectangularity (Rec), Ellipticity (Ell) and Aspect Ratio (AR). There were no significant difference in the mean size and shape indices of the otolith between females and males. The relationship between TL - OL follows the power function: OL = 1.027993 * TL0.198863 (R2 = 13.18%). The low value of R2 seems to be due to the mixing of more than one stock of skipjack tuna in the sample. Separation of observation data in the relationship between TL - OL into two different stocks can increase the value of b or R2. It is possible for skipjack tuna in the Sulawesi Sea to consist of two different stocks. The separation of the two stocks can mainly be determined by the size of the otolith, the size of the otolith of stock 1 is relatively large compared to stock 2. The relationship of ln (TL) - ln (OL) stock 1 and stock 2 were ln (OL) = -2,282 + 0,610 * ln (TL) (n = 53; r = 0.91) and ln (OL) = -2,363 + 0.566 * ln (TL) (n = 43; r = 0.64). It is possible that stock 1 is the stock of the Indian Ocean and stock 2 is the stock of the Western Pacific Ocean. To test this hypothesis, genetic studies are needed.