This study aimed to identifying the level of decision making skill among students in grade eleven in Oman and to identifying the most common cognitive styles among them. It also aimed at exploring the statistically significant differences between students according to gender and specialization variables. Finally, it aimed to knowing the cognitive styles that most predict decision making skill. The sample of the study consisted of (500) male and female students in grade eleven in Oman. Four instruments used which are: Embedded Figures Test to measure the cognitive style field (dependence- independence), Verbal Situations Test to measure the cognitive style (reflectivity- impulsivity) and Verbal Situations Test to measure the cognitive style (cautiousness- risk taking). Verbal Situations Test (developed by the researcher) To analyze data statistically, the researcher used one sample T-test, median, frequencies, manova and stepwise multiple regression. The results indicated the following: - High level of decision making among students. The most common cognitive styles among students are (field dependence), (impulsivity) and (cautiousness). There are statistically significant differences in decision making skill between males and females in favor of females. However, there are no statistically significant differences in decision making skill according to specialization. The results also showed statistically significant interaction between gender and specialization in their effect on decision making skill. The results indicated that the cognitive styles ( impulsivity reflectivity) and (risk- taking-cautiousness) are predictors of decision making skill among the sample, while the cognitive style field (dependency- independency) is not a predictor of decision making skill among grade eleven students in Sultanate of Oman.