Urinary mycobacteriosis is rare although nontuberculous mycobacteria (NTM) are frequently isolated from the urine. 63 patients (pts) with NTM isolated from the urine were followed up 1 to 8 years; the most frequent complaint was low back discomfort (91% pts), while the leading laboratory findings were pyuria (72%) and microscopic hematuria (57%). Intermittent proteinuria was present in the minority (35%) showing nonnephrotic range. IVP revealed pathologic findings in 72% of the pts. During follow up none of the pts have had clinical or laboratory progression of the disease. Standard antituberculosis therapy has been applied in 22 pts, only 4 with satisfactory response. -Evidence of NTM does not exclude search for other possible causes of hematuria or pyuria; -renal mycobacteriosis, even if it does exist as an entity, is not as aggressive as tuberculosis; -standard treatment regimen for tuberculosis does not have positive effects in majority and susceptibility testing is necessary.