A year long monitoring of sea water feed, product distillate and potable water samples from Al-Jubail MSF plant in the eastern coast of Saudi Arabia was carried out to detect the possible presence of toxic organic compounds. Similar study was also undertaken in Al-Khobar and Al-Khafji plants for shorter periods (3 – 5 months). Several samples of sea water and product water before and after chlorination and blended potable water were periodically collected and analysed for volatile and non-volatile organics by well established methods employing Gas Chromatographic (GC) and Gas Chromatography/Mass Spectrometric (GC/MS) techniques. Several of the detected organics were quantitatively estimated using standard chemicals, others were tentatively identified by GC/MS detector using a computerized library search facility. Harmful effects of these compounds on humans in the light of the available informations on their toxicity as well as guide line limits set by WHO for some detected pollutants have been discussed.