A sensitive and fast method is described that solid phase extraction (SPE) using dichloromethane, followed by gas chromatograph-mass spectrometry for the determination of environmentally carcinogenic naphthalene, anthracene, phenanthrene and fluorene (NAPF) from the Bangsai river water near the Dhaka mega city of Bangladesh. The method was applied to identify and quantify the carcinogenic NAPF in water samples collected from surface and 30 cm depth of water. Methanol (50 ml) pretreated and filtered water samples were applied directly to a C18 SPE column. The carcinogenic NAPF were extracted with dichloromethane and the NAPF concentration was obtained to be 0.39 to 54.98 ppm. The factors influencing SPE e.g., absorbent types, sample load volume, eluting solvent and temperature, were investigated. A cartridge containing a C18 absorbent and using solvent gave a better performance for the extraction of NAPF from the Bangsai river water samples. Average recoveries exceeding 75% could be achieved for toluene at 25 °C with a 2.6% RSD.