Context: For practicing health care professionals, waiting for a teachable moment to identify a gap in knowledge could prove critical. Other methods are needed to help health care professionals identify their knowledge gaps. Objective: To assess the effect of performance feedback on Athletic Trainers' (AT) perceived knowledge (PK) and likelihood to pursue continuing education (CE). Design and Setting: Pre-test, post-test control-group design to measure PK and likelihood to pursue CE before and after assessing actual knowledge (AK) in an on-line classroom (Campus Edition 6; Blackboard Inc.). Participants: We randomly sampled potential participants (n = 2000) from the National Athletic Trainers' Association membership directory and then randomly assigned (n = 103/2000, 5.1%) them to control (n = 58) or experimental groups (n = 45). Interventions: Performance feedback following the AK assessment in the experimental group. Main Outcome Measures: We assessed PK and likelihood to pursue CE before and after the AK assessment. We calculated differences between pre-test and post-test scores and knowledge gap. Two independent samples t-tests examined the effects of feedback on the dependent measures. Multiple linear regression was used to predict post-test likelihood to pursue CE using three variables: PK, pre-test likelihood to pursue CE knowledge gap. Results: We found a significant difference (68.2%) between groups for likelihood to pursue CE (P = 0.01, ES = 0.45). The experimental group demonstrated a 13.8% (pre-test = 4.12 plus or minus 1.32, post-test = 4.78 plus or minus 1.13) increase in likelihood to pursue CE, while the control group increased 4.4% (pre-test = 4.60 plus or minus 1.07, post-test = 4.81 plus or minus 1.08). Pre-test likelihood to pursue CE was a significant predictor of post-test likelihood to pursue CE (r = 0.74, R[superscript 2] = 0.55, P = 0.05). We observed a moderate relationship between pre-test knowledge gap and post-test likelihood to pursue CE (r = 0.31, R[superscript 2] = 0.10, P less than 0.01). Pre-test knowledge gap was a significant predictor of post-test knowledge gap (r = 0.88, R[superscript 2] = 0.77, P less than 0.01). Conclusions: Knowledge assessment alone increases the likelihood to pursue CE, yet when feedback is provided ATs are more likely to pursue CE. (Contains 1 figure and 2 tables.)