This study was carried out in order to diagnose cases of medicolegal deaths specially those where clinical signs and postmortem pictures are not even the available laboratory test may confused with other types of diseases which may lead to difficult or miThree types of medico legal deaths were selected (electric shock, drowning, starvation) where the previously mentioned evidence used for diagnosis are obscure.In this study sixteen adult male albino rats were divided into four equal groups as follows:• First group: animals were died by cervical dislocation.• Second group: animals were died by electric shock by applying two hundred and twenty volts (220V) current.By comparing the residue of organochlorines in tissues and egg yolks of cattle egrets, it was observed that the levels of all detected organochlorines in egg yolk samples are higher than those found in liver and abdominal fat tissues. It was also found thII. The residue of pyrethroids in tissues and eggs of cattle egrets:Estimation of the pyrethroidal residues in liver, abdominal fat and egg yolk samples of cattle egrets revealed that all analyzed pyrethroidal compounds (tetramethrin, cyhalothrin, permethrin and cypermethrin) were not detected in any of examined samples eThe second part of this study was carried out to elucidate the toxic effect of the synthetic pyrethroid (fenpropathrin) on chromosomes of bone marrow cells and some biochemical parameters in serum of albino rats.Thirty mature albino rats were divided into three groups each group contain 10 rats. The first and second group administered fenpropathrin orally at a dose of 150 LD50 (1.4 mg/kg b.wt.) and 1100 LD50 (0.7mg/kg b.wt.), respectively for 14 consecutive day