This study developed a scale of tolerance of ambiguity (as an aspect of personality or cognitive style) related to second language learning. The scale was used to discover if tolerance of ambiguity influences students' use of various second language strategies. The research was carried out with students of Spanish at the university level. Multiple regression analysis provided partial confirmation of several specific hypotheses regarding tolerance of ambiguity. Strength of motivation, attitude, and concern for grade were also found to influence use of strategies.