Introduction: Self-directed learning skills are necessary for modern education and can be affected by different style of decision making. This study aims to evaluate the relationship between decision –making style and self-directed learning among anesthesiology students.

 Materials and Methods: This descriptive-correlational study was conducted on 147 Mashhad School of Nursing and Midwifery anesthesiology students in 2014, using census approach. General Decision-Making Style Inventory (Scott & Bruce, 1995) and Self-Directed Learning Instrument (Cheng et al, 2010) was used. The instruments’ content validity confirmed by experts, and their reliability calculated by Cronbach’s alpha coefficient (0.74 and 0.94 respectively). data were analyzed using SPSS software version 21 and chi-square, Mann-Whitney, Kruskal-Wallis and Spearman correlation tests. The probability of type I error (α) for all tests was set to 0.05.

 Results: The mean age of participants was 25.38 ± 8.66 and most participants were female (85.7%). The dominant decision making style and self-directed learning domain in most participants were rational decision-making style and learning motivation domain, respectively. Scores in all aspects of decision-making and self-directed learning were significantly different in both sexes with the exception of intuitive decision making style and interpersonal communication. Self-directed learning was positively correlated with rational decision-making style (+ 0.64) and negatively with avoidant (- 0.68) and spontaneous (- 0.71) decision-making styles and rational decision-making style negatively correlated with avoidant (- 0.35) and spontaneous (- 0.68) decision-making styles.

 Discussion & Conclusion: Rational decision-making style had the strongest relationship with self-directed learning among student.