During an 11-month prospective study, urine cultures were performed on 5685 samples obtained in three hospital units. The use of a selective medium improved the recovery of antibiotic-multiresistant corynebacteria (AMC): 703 isolates (12.4%) compared with 88 isolates (1.6%) on sheep blood agar. Corynebacterium group D2 (CGD2) was isolated in 80.5% of urines yielding greater than or equal to 10(5) AMC ml-1 whereas Corynebacterium jeikeium represented 80.2% of isolates with less than 10(5) AMC ml-1. Among 16 patients with greater than or equal to 10(5) ml-1 C. jeikeium none had signs of urinary tract infection. In contrast, among 56 patients with greater than or equal to 10(5) CGD2, 40 (71%) had abnormal urinary sediment (mainly apatite or struvite crystals) and 29 (52%) had clinical signs of urinary tract infections sometimes complicated by lithiasis (seven cases) and alkaline-encrusted cystitis (two cases).