Background & Objective: Mycobacterium leprae is the cause for leprosy which is a contagious disease in many developing countries. These diseases have always been a dreadful one for its unpleasant clinical symptoms and the disabilities it causes. It has the most prolonged cell division time of all bacteria (12-14 days). Its incubation period is long (3-5 years) even 40 years has been reported. The complications which it leaves are irreversible and it bears a heavy socio-mental burden on the individual and the society. WHO has listed 91 countries with leprosy. The goal of the present study was the early diagnosis of the disease before the emergence of unpleasant clinical symptoms and popularizing molecular method of PCR in place of the conventional method of slit skin smear which is not a precise or reliable method.

  Methods: In this study 40 slit skin smear and the same number of skin biopsies were taken from patients referring Bababaghi Hospital and samples from ear lobes and eyebrows were taken. Slit skin smears were stained with Zeihl-Neelsen method and examine microscopically. At the same timy biopsy specimens were extracted.

 Results: Of 40 samples, three slit-skin specimens (7.5%) had positive smear result, while 14 (35%) biopsies had PCR positive result. The rest (11 cases) probably had TT or borderline forms of BB, BT, BL).

 Conclusion: The results showed that SSS is not a precise and reliable method for diagnosing leprosy especially in TT form which is always negative direct smear. Also direct smear method and clinical symptoms are not accurate or reliable methods in estimating the rate of disease prevalence.