Abstract: In Tunisia, we have an increasingly growing sewage sludge production. Therefore, evaluation of its valorisation is essential. Composting has emerged as a valuable route for the disposal of urban waste, with the prospect of applying composts on arable fields as organic amendments. A comparative study was made for major nutrient elements or macronutrients (include carbon, nitrogen, phosphorous, potassium) and the micronutrient elements mostly used (manganese and magnesium) present in the activated sludge taken from the municipal wastewater plant of Charguia in the capital of Tunisia and the produced compost made from the above sludge (13.37 C/N ratios). K, Fe and Mn concentrations were more important in the maturity compost. The original sludge shows a higher C, N, P, Ca and Mg contents. An important observation was that the amount of heavy metals and E. coli present in the final product is lower than the amount mentioned for the waste compost use in French norms, showing that the final compost was not toxic.