Colicin typing, biotyping, phase typing and in vitro antimicrobial susceptibility testing were performed on clinical isolates of Shigella sonnei from three different geographical locations. Results of 93 strains from Kuwait, 61 strains from Saudi Arabia and 23 strains from Bangladesh were compared. Of 169 strains of S. sonnei tested, 75% belonged to colicin type 6/11. It was the most common colicin type in all three countries. However, differences in antimicrobial susceptibility patterns were observed. The resistance pattern in 62% of resistant strains from Kuwait was tetracycline – trimethoprim/sulpha-methoxazole – trimethoprim (TE-TMP/SMZ-TMP). Saudi Arabian strains were of the same resistance pattern with additional resistance to ampicillin (AM) AM-TE-TMP/SMZ-TMP (34%) which was seem more often than TE-TMP/SMZ-TMP (26%). Most of the strains (65%) from Bangladesh were sensitive to all the antimicrobial agents against which they were tested. Of the 8 strains which showed resistance, 50% were resistant to tetracycline alone. Study of carbohydrate fermentation of 12 sugars which were incubated for 21 days did not aid in discriminating different bioty