The study examined (1) the extent of APA Style writing knowledge and understanding among a purposive sample (N = 118) of incoming MSW students; (2) determined the impact of a structured workshop on their level of APA knowledge; and (3) examined the influence of undergraduate academic major on level of knowledge and understanding of APA Style writing rules. The predominantly White female sample were new enrollees attending the MSW Program orientation. Most were undergraduate psychology, social work, and sociology majors. Other undergraduate majors included child/family studies, history, communications, and interdisciplinary studies. Data were collected using the APA Knowledge and Understanding (AKU) pretest and posttest Survey that includes 18 Likert-style items. The scoring range on the AKU Survey is 1 (Not difficult at all) to 5 (A great extent of difficulty), and the "alpha" coefficient for the survey items was 0.925. The overall mean pre-test score for the sample was 2.96. Posttest scores following the workshop were significantly improved for all APA study variables, with a combined mean score of 4.36. Undergraduate academic major significantly impacted level of APA knowledge and understanding among the sample ("Lambda" (162, 729) = 0.119, p = 0.005). Study results strongly support the use of structured workshops for APA Style writing rules instruction.