We describe the first "Mycobacterium paraffinicum" (unofficial taxon) pseudo-outbreak in a tertiary-care medical center. Fifteen clinical nontuberculous mycobacterium isolates from 10 patients were initially identified by biochemical tests and high-performance liquid chromatography as Mycobacterium scrofulaceum. However, further testing by molecular analysis revealed "M. paraffinicum." Epidemiological and environmental investigation determined that the ice machine was the source of the pseudo-outbreak.