We investigated the relation between students' physics anxiety and their physics performance, and whether this relation differs as a function of gender. To measure students' levels of physics anxiety, we used the Physics Anxiety Rating Scale, which contains 32 items in four categories: course/test anxiety, anxiety about the lack of physics knowledge, math anxiety, and physics laboratory anxiety. Reliability analysis using 76 algebra-based introductory physics students showed a high level of internal consistency for the entire scale as well as for each of the four categories. Females reported significantly higher levels of physics laboratory anxiety than males. No other significant gender differences in anxiety levels were observed across the other three categories. In terms of the relation between physics anxiety and performance, course/test anxiety was significantly negatively correlated with the midterm exam for females but not for males, while lack of physics knowledge anxiety was significantly negatively correlated with both the midterm and final exams for the males but not for the females. Finally, we found a significant positive relation between physics laboratory anxiety and the final exam for the males but not for the females, even though females reported significantly higher levels of physics lab anxiety than males.