The effect of opioid and non-opioid analgetics (promedol, metamizol, novocain) on American cockroach behavior was studied. The method of "hot plate" (45^oC) combined with "open field" was adapted for the cockroach. The agents were injected into the insect’s hemolimph. Estimation of behavioral effects (duration - 6 min) was based on the registration of horizontal locomotor activity (HA), latent period of first "rearing" (LP) and summary time that the insect spent on the vertical wall of the chamber (T). Promedol, in the dose of 0.12 mg/g, decreased HA with 31%, T with 20% and increased LP with 250%. It may be concluded that this opioid possesses high affinity corresponding to some type of receptors in the cockroach nervous system. Metamizol, in the dose of 2 mg/g, decreased HA with 66%, T with 62 % and increased LP with 380%. Novocain did not influence the insect’s behavior in "hot plate", but disrupted the motor activity and movement of extremities in the "open field" (20^oC). The developed method may be suggested as an alternative one (in the view of bioethic problems) for screening new biologically active agents.