Heavy metals (Cadmium Cd, Lead Pb and Mercury Hg), organochlorine pesticides and testesterone residue levels were assessed in some fish species sold in Cairo Governorate. A total of one hundred samples from five different fish species Oreochromis niloticus (Tilapia), Clarias gariepinus (Nile catfish), Lates niloticus (Bagrus Bayad) and, Scomberomorus cavalla (Mackerel), Thunnus albacares (Tuna) were purchased from vendors in Cairo governorate, Egypt. Samples were analyzed for Cd, Hg and Pb by Flame Atomic Absorption Spectrometer. The organochlorine pesticides were determined with Agilent gas chromatograph GC. Methyl testesterone hormone levels were determined wit Rida screen ELISA kit for tissue. Cd concentrations ranged from 0.0466 ppm to 0.0686 ppm for all fish species with highest levels in Tilapia. Total mercury ranged from 0.075 ppm to 0.151 ppm for all fish species with highest levels in Mackerel. Pb concentrations ranged from 0.06ppm to 0 .44 ppm with highest levels in Nile catfish. Organochlorine pesticides, such as (gamma-BCH, AlphaBCH, delta- BCH, aldrin, p.p'-DDE, endosulfan, dieldrin, p,p'-DDT, p,p'-DDD, heptachlor, heptachlor epoxide, endosulfan, endrin, gama- chlordan and methoxychlor) were investigated. Five organochlorine (endrin, p,p'-DDD, methoxychlor, gamma-BCH and delta- BCH) pesticides were detected in all studied fish samples. Endrin and p,p'- DDD were the most abundant pesticide residue in the studied tissues of all fish species except Tuna. The highest values of Methyl testosterone residue were 2 ppb and found in (5) 25% of Tilapia fish samples.