Abstract: Over the past several decades, the use of cross-sectional imaging has steadily increased largely because of increasing refinements in imaging technology. The progressive improvement in both spatial and temporal resolution of imaging modalities over the years has enabled radiologists to diagnose and characterize disorders with increasing accuracy. However, improved resolution has led to the increased detection of imaging findings that may or may not be clinically relevant. Such incidental findings or "incidentalomas" may be difficult to differentiate from clinically relevant lesions. Radiologists may provide disparate recommendations regarding incidental or indeterminate findings when interpreting results of gynecologic and obstetric imaging examinations in routine clinical practice. Vague recommendations pose challenges for referring clinicians who are unable to determine the clinical relevance of such lesions. Therefore, a general awareness of incidental lesions for any given abdominal or thoracic organ is important for obstetrician-gynecologists involved in the management of patients who require imaging studies. The aim of this monograph is to aid obstetrician-gynecologists in the detection, characterization, and management of incidentally detected lesions that may be encountered on routine women's imaging examinations.