Purpose To determine the rate of film-labeling errors and to describe a process for improved plain-film image labeling and the clinical outcomes from this process improvement. Methods Image-labeling errors (absent or incorrectly assigned left or right lateral identifier marker, absent or incorrect patient-identifying number, absent or incorrect examination date, incorrect marker placement, absent technologist initial marker, or incorrect body-part order) were measured among 2,536 consecutive plain-film radiographs over a 2-week period. Following a process improvement initiative based on failure mode effectiveness analysis, left-side and right-side indicator markers, patient demographics, and date labels were identified as the most common sources of error. An improvement initiative using larger and colored left and right lateral indicator markers, an automated process to label patient demographics, and direct patient verification of identification was begun. The numbers of labeling errors were again assessed in 2,421 consecutive plain radiographs over a 2-week period. The error rates before and after the improvement initiatives were compared. Results Plain-radiographic labeling errors occurred in 62 of 2,536 (2.4%) images before the improvement initiative. Labeling errors were reduced to 17 of 2,421 (0.70%; 95% exact binomial confidence interval, 0.4% to 1.1%; P < .001, chi-square test) by using the improvement tools. Conclusions Plain radiographic image labeling can be improved using bar-code reading of patient demographic information, linked to patient Digital Imaging and Communications in Medicine modality work lists and image printing. Patient verification of demographic information is key and can be electronically managed. Lateral marker identification can be improved with larger (more easily read) and color-coded indicators.