The appearence of Shigella with multiple resistance to drugs, turned up in Rio de Janeiro with identical gravity to that already resistance in other countries. In the period 1950-1959, in 51 strains tested, 9,8% showed infectious resistance to one and various drugs, while in the period 1960-1969, the percentage, rose to 21,3% in 61 strains. Of 112 strains of Shigella tested, 74 were flexneri, 20 sonnei and 18 dysenteriae, is being noted the predominance of resistance to, 3,4 and 5 drugs in conjunction with the others in the fexneri group.