Worked examples have proven to be effective for knowledge acquisition compared with problem solving, particularly when prior knowledge is low (e.g., Kalyuga, 2007). However, in addition to prior knowledge, executive functions and fluid intelligence might be potential moderators of the effectiveness of worked examples. The present study examines the roles of the executive functions of working memory capacity and shifting, as well as the role of fluid intelligence for knowledge acquisition in the presence or absence of worked examples. Seventy-six university students learned to solve statistical problems either with worked examples or through problem solving (the absence of worked examples). Results showed that shifting and fluid intelligence, but not prior knowledge and working memory capacity, moderated the effect of the presence of worked examples on knowledge acquisition. The higher the shifting ability and fluid intelligence were, the lower was the benefit of worked examples compared with problem solving. Learning environments did not differ with respect to cognitive load, and cognitive load was not correlated with working memory capacity, but it was correlated with fluid intelligence. These findings suggest that other important cognitive functions, such as shifting and fluid intelligence, might be more important than prior knowledge or working memory when worked examples are compared with problem solving. Future research can further examine whether the relative contribution of the different functions is likely to depend on the characteristics of the respective tasks--that is, whether a task puts a high or low demand on these cognitive functions.