The present study was conducted to follow up the residues of the insecticide fenitrothion (Sumithion 50% EC), recommended for con­trol of aphids, and the fungicide pyrazophos (Afugan 30% EC), recom­mended for powdery mildew, on and in squash fruits. The results indicat­ed that both O.P. pesticides were extremely degradable when they were applied on fruitful squash plants. The residues half life values on and in squash fruits for fenitrothion and pyrazophos were 24 and 26 hours, re­spectively. Residues of both pesticides on and in squash fruits reached negligible levels only two days after treatment with total loss of about 98%. Those residue levels were much less than the established maxi­mum residue limits (MRLs) of both chemicals which confirm that two days after treatment is quite enough as a waiting period, i.e. pre-harvest interval (PHI), before markting or consuming of treated squash fruits. The results also indicated that the peeling of the fruits removed 96% of fenitrothion residues and almost all the residues of pyrazophos for all intervals including the fruits collected an hour after appl: ca!::.-.r. The peeled fruits were almost pyrazophos residue free or had negligible levels much lower than the established MRL for fenitrothion.