OBJECTIVES: The Orthopaedic In-Training Examination (OITE) is administered yearly to assess a resident's progression, compare his or her performance with that of other residents, and evaluate the educational structure of a residency program. The American Board of Orthopaedic Surgery (ABOS) Part I examination is used to ensure competence in orthopedic knowledge and must be passed to achieve certification. Previous studies have correlated OITE and ABOS performance, but analysis between OITE subsection performance and ABOS Part I examination performance has not been reported. The purpose of this study was to evaluate the relation between individual OITE subsection performance and overall ABOS Part I performance. METHODS: Performance on the 12 subsections comprising the OITE from 1999 to 2009 was evaluated and compared with overall ABOS Part I examination performance. Spearman correlation coefficients (SCCs) were used to quantify the association between OITE subsection and overall ABOS percentile ranks. RESULTS: The OITE subsections of musculoskeletal trauma (SCC 0.29; P = 0.0002), hip and knee reconstruction (SCC 0.21; P = 0.0064), spine (SCC 0.16; P = 0.04), orthopedic science (SCC 0.17; P = 0.03), and orthopedic disease (SCC 0.18; P = 0.02) correlated with ABOS percentile ranks. Five of the top seven subsections by question volume on the OITE were found to correlate with ABOS performance. CONCLUSIONS: OITE subsections with greater representation and breadth of subject matter had stronger performance correlations with ABOS Part I examination performance. These findings may allow residency training programs to better predict ABOS Part I performance of their residents by evaluating particular subsections on the OITE in addition to overall OITE performance.