Pathogenic leptospiras (1,424) isolated from natural waters and wet soils in Malaysia comprised 29 different serovars (synonym serotypes). All except two of the serovars had been found previously in Malaysia. The exceptional serovars were werrasingha, an Autumnalis serogroup member originally isolated in Ceylon, and a new serovar designated evansi. Serovar evansi had serological affinities with serovar ranarum which was isolated from the kidney of a frog in Iowa. The large variety of serovars found in jungle areas was consistent with similar previous findings of diverse serovar infections in troops who had operated in Malaysian jungles.