A kinetic study of the pyrolysis of municipal solid waste (MSW) was carried out by thermogravimetric analysis (TGA). Different runs were performed at heating rates of 5, 10 and 150C/min. The effect of the N2, CO2 and O2 gas with different combination in the process was also evaluated. The results show that the most weight loss was obtained when the MSW was treated at a temperature interval of (20-750)0C which led to a weigh loss of 95%. The kinetic study of the pyrolysis process showed also the gas mixture used in the process effect also the activation energy of the process and the presence of the CO2 in the increased the activation energy (Ea) to 56 kJ/mol. Higher concentration of CO2 in the process lead to increase in the activation energy which is not optimal for the reaction. The treated and the untreated samples were incubated and the biological activity was observed. The results show that the pretreated samples did not have any biological activity. From these results it could be concluded that the thermal pretreatment could be an alternative way for of waste for long period of time, which could have significant impact in i.e. for transportation and durability during storage.