The objectives of this study were twofold: (1) To determine the predictors of performance on a medication dose calculation test in first year baccalaureate nursing students. The variables studied were: level of math anxiety; math personality; arithmetic ability; program of study; age; and the number of strategies used to prepare for a medication dose calculation test. (2) To determine the factors that affect math anxiety. The variables studied were: arithmetic ability, program of study, math personality, the number of test preparation strategies used and age. Participants consisted of a convenience sample (n = 163) from the first year of a Canadian baccalaureate nursing program. Participants completed a mathematics test, which served as a baseline measure of arithmetic ability. They also completed a series of online questionnaires on math anxiety and math personality, age and program of study (compressed program vs. collaborative program). Participants then completed a medication dose calculation test after which they were asked how many different strategies that they had used in preparation for the test. Performance on the medication dose calculation test was regressed on arithmetic ability, mathematics anxiety, program of study, mathematics personality, the number of test preparation strategies and age. Math anxiety was regressed on pretest score, program of study, math personality, the number of test preparation strategies used and age. The variables found to predict performance on the medication dose calculation test were anxiety and program of study. Of the predictors investigated, only the “Inchworm” math personality and number of test preparation strategies used by students significantly predicted anxiety. Strategies to improve nursing students’ ability to perform dosage calculations should incorporate anxiety-reducing tactics as anxiety was found to be a key predictor of performance on the medication dose calculation test. These strategies should focus on supporting students who possess an “inchworm” math personality.