The early case detection followed by WHO/MDT is the most important in leprosy control program not only for the destruction of linkage of infection but also the prevention of disability in leprosy. PIME Sisters leprosy program has been carrying out active case detection for leprosy since 1986 in Khulna, the third biggest metropolitan city in Bangladesh. The relation between several detection modes and their associated disability grading was analyzed in order to see the contribution of each detection mode to disability grading. The disability grading of new registered patients from 1995 to 1997, 1, 115 cases in total was analyzed according to its detection mode. Voluntary reporting patients from “out of control area” had both high disability grading of G=2 (38.0%)and high MB rate (39.3%). On the other hand voluntary reporting paticnts in control area had less disability grading of G=2 (12.2%)and less MB rate (25.3%). The number of patients referred by local doctors was still small and had both high disability grading of G=2 (27.0%)and high MB rate (51.4%). Children detected under school surveillance did not have any marked disability of G=2 (0%)and were almost PB patients (88.6%). (Prevalence rate of school surveillance was low.) Patients detected under general surveillance had low disability grading of G=2 (2.6%). The disability grading (G=2) of voluntary patients from control area (12.2%) was three times as much as that of patients from general surveillance (2.6%). Lastly patients of family contacts who were aware of the first symptoms had relatively less disability grading (5.9%). The small number of patients referred by local doctors (3.3% of total number) with high disability grading meant that there would be still great need of information programs on leprosy for local medical professions to think about leprosy. The high disability grading of patients from “out of control area” meant that the more effective leprosy control program should be done in “out of control area”.