With the objective of evaluating the effect of the treatment with inert dusts on the quality of corn seeds, a research was conducted at the Instituto Agronômico do Paraná - IAPAR, in Londrina, state of Paraná, Brasil, in the period of september of 1996 to july of 1997, using corn seeds variety IAPAR 26, produced in 1995/96. The treatments studied were: check (non treated seeds); Deltamethrin (2g a.i./ton seeds) + Pirimiphos methyl (20g a.i./ton seeds); commercial formulation of inert dust, amorphous silica and silicates (2kg/ton seeds); Deltamethrin (2g a.i./ton seeds) + Pirimiphos methyl (20g a.i./ton seeds) + Captan (1200g a.i./ton seeds) and inert dust (2kg/ton seeds) + Captan (1200g a.i./ton seeds). The evaluations were made at bimonthly intervals, consisting of: standard germination test, vigor (cold test without soil and seedling emergence in the field), index of infested seeds and the moisture content. In the conditions the work conducted, was concluded that the use of the inert dust in the treatment of corn seeds, separately or in mixture with fungicide, it didn´t interfere in their quality, presenting performance similar to the treatments in wich where conventional insecticides were used.