In outbreak years, poplar leaf miner Proleucoptera sinuella is an economically significant pest of poplar trees. Such an outbreak has started in 2000 in some poplar nurseries and plantations in Vojvodina and it is still in progress. Its biology and potential control has been studied during 2002 in the Poplar Research Institute Laboratory and Experimental Estate. During 2002, Proleucopera sinuella has developed three generations of which the first one is the most numerous one, and the third is the least numerous. Several caterpillars develop in the mines and they undergo four instars. Adult caterpillars leave the leaf mines and turn into pupal stage in the white spun cocoon on the leaf surface. The pupae of the third generation overwinter. Obtained results sugests that suppression can be carried out at the beginning of butterfly eclosion, i.e. before the mass oviposition, by treating the poplars with chemical preparations.