Human anatomy is a foundational course in nursing education, however, there is growing concern that students do not retain enough anatomical knowledge to successfully apply it in clinical settings. The aim of this study was to determine retention level of anatomy knowledge among second-year nursing students from their first-year anatomy class, and to determine if there is a difference in level of retention based on organ system. For each system, second-year students were asked to answer 9 to 11 multiple-choice questions (MCQs), and the scores from these quizzes were compared to matched test items from their first-year anatomy examinations. There was a significant decrease in the overall mean score from 83.05 ± 8.34 (±SD) in first year to 54.36 ±12.9 in second year (P = 0.0001). Retention levels were system specific. System-specific knowledge retention was highest for the gastrointestinal system (89.7%), respiratory system (88.5%), and genitourinary system (83.6%). This was followed by the integumentary system (80.1%), special senses (79.4%), nervous system (74.9%), and musculoskeletal system (69.3%). Retention was lowest for the lymphatic system (64.3%), cranial nerves (58.8%), vascular system (53.9%), and head and neck (42.6%). The present study shows that nursing students' anatomy knowledge retention was comparatively higher than rates reported by others in medical and allied-health students. The researchers are now investigating knowledge retention in third- and fourth-year nursing students. Further investigation into why retention is higher for specific systems and intervention strategies to improve knowledge acquisition and retention in nursing students is recommended.