Determinate growth habit in sesame is not available in nature originally. The character was a mutant induced by gamma rays and has the potential to make possible mechanised harvesting in sesame by enabling synchronous flowering. Though no detailed study on fatty acids of determinate types has been recently performed, much material is available on the genotypes of indeterminates. Therefore, the present study aimed to compare determinate and indeterminate types of sesame with regard to oil content and fatty acid composition. A total of 10 genotypes, six determinate and four indeterminate types, were grown in a randomised complete blocks design with three replications at Antalya in the growing seasons of 1998 and 1999. The seeds from each plot in the two years were subjected to oil extraction and subsequent fatty acid analysis using gas chromatography. The oil contents of the determinate genotypes were found to be close to their wild types and sibs. However, the low seed yield of these genotypes resulted in lower oil yields compared to indeterminate types. In addition, it was seen that the determinate genotypes were found to be of higher oleic acid content and lower linoleic acid content. In conclusion, the fatty acid composition of determinate types was found to be satisfactory. However, the oil yield of these genotypes has to be improved by increasing their seed yield.