Sewage sludge is usually treated before disposal. Treatment options include screening, thickening, disinfection, stabilization, conditioning / dewatering and incineration. During these treatments there is the potential for some organic pollutants present in the sludge to be lost. Loss mechanisms include volatilization, biological degradation, abiotic/chemical degradation and extraction with excess liquors. Some chemicals are likely to be effected more than others. Some treatments actually increase the concentration of selected compounds. This review considers how sludge treatment may effect the organic chemical content of the sludge and stresses the need for more research. Most studies have concentrated on the effect of sludge digestion on organic pollutants, however, other treatments may be just as important. Tentative suggestions are made for the likely behaviour of several groups of compounds.