The purpose of the present series of experiments was to study the DDVP residues in sausages and bacon resulting from the placement of Mutox strips in the sale-rooms of butchers' shops. After extraction from the samples, Dichlorvos was determined thin-layer chromatographically using cholinesterase inhibition. The results obtained show that neither bacon nor lard should be kept for a prolonged period in a sale-room where Mutox strips are hanging. Sausages hanged up at a distance of 1 m from the Mutox strip contained no DDVP residues.