Rationale: Radiologist reports of pulmonary nodules discovered incidentally on computed tomographic (CT) images of the chest may influence subsequent evaluation and management.Objectives: We sought to determine the impact of the terminology used by radiologists to report incidental pulmonary nodules on subsequent documentation and evaluation of the nodules by the ordering or primary care provider. Methods:We conducted a retrospective cohort study of patients with incidentally discovered pulmonary nodules detected on CT chest examinations performed during 2010 in a large urban safety net medical system located in northeastern Ohio. Measurements and Main Results:Twelve different terms were used to describe 344 incidental pulmonary nodules. Most nodules (181 [53%]) were documented in a subsequent progress note by the provider, and 140 (41%) triggered subsequent clinical activity. In a multivariable analysis, incidental pulmonary nodules described in radiology reports using the terms density (odds ratio [OR], 0.06; 95% confidence interval [CI], 0.01-0.47), granuloma (OR, 0.07; 95% CI, 0.01-0.65), or opacity (OR, 0.09; 95% CI, 0.01-0.68) were less likely to be documented by the provider than those that used the term mass. Patients with nodules described in radiology reports using the term nodule (OR, 0.15; 95% CI, 0.02-0.99), nodular density (OR, 0.09; 95% CI, 0.01-0.63), granuloma (OR, 0.06; 95% CI, 0.01-0.69), or opacity (OR, 0.05; 95% CI, 0.01-0.43) were less likely to receive follow-up than were patients with nodules described using the term mass. The factor most strongly associated with follow-up of pulmonary nodules was documentation by the provider (OR, 5.85; 95% CI, 2.93-11.7).Conclusions: Within one multifacility urban health system in the United States, the terms used by radiologists to describe incidental pulmonary nodules were associated with documentation of the nodule by the ordering physician and subsequent follow-up. Standard terminology should be used to describe pulmonary nodules to improve patient outcomes.Keywords: solitary pulmonary nodule; multiple pulmonary nodules; CT scan; clinical decision making Author Contributions: Full access to all of the data in the study and responsibility for the integrity of the data and the accuracy of the data analysis: J.D.T.; study conception and design; collection and assembly of data; analysis and interpretation of the data; critical revision of the manuscript for important intellectual content; and administrative, technical, or material support: all authors; drafting of the manuscript: M.N.I., E.S., A.M.H., V.K., and J.D.T.; statistical expertise: A.M.H., V.K., C.S., and J.D.T.; obtaining of funding: J.P., M.C., C.S., and J.D.T.; and study supervision: M.N.I., A