This study aimed to determine whether fatalistic beliefs were associated with elevated levels of glycated hemoglobin (HbA1c) and to establish the role of religiosity in this relationship. A cross-sectional survey was conducted on a sample of 183 Jewish adults with diabetes visiting a large medical center in northern Israel. Self-administered questionnaires assessed level of religiosity, fatalistic beliefs, diabetes management behaviors, and demographic/personal characteristics; laboratory tests were used to measure HbA1c. Multivariate regression indicated that fatalism was significantly associated with HbA1c (ÎČ = 0.51, p = 0.01). The association was no longer statistically significant after including self-reported religiosity in the model (ÎČ = 0.31, p = 0.13). This phenomenon is likely due to a confounding relationship between the religious/spiritual coping component of the fatalism index and self-reported religiosity (r = 0.69). The results indicate that addressing fatalistic attitudes may be a viable strategy for improving diabetes management, but call for a better understanding of the interplay between religiosity and fatalism in this context.