Susceptibility levels for the adult bed-bug, Cimex lectularius, in Belo Horizonte, Minas Gerais – Brazil, to DDT, were determined during the period 1985 to 1986. The test results showed that a 4% dosage of DDT is not enough to kill 55% of the insects. The data are sufficient to show that there exists bed-bug resistance to DDT in Belo Horizonte.