Abstract: The effect of temperature, dry solids and C/N ratio on the growth of E. fetida and on vermicomposting of waste activated sludge was studied in a small-scale laboratory experiments. The maximum growth rate in 25°C, 15-20% dry solids and a C/N ratio of 15 were 19±1, 21±2 and 20±2 mg/worm/day, respectively. Moreover, changes in the physicochemical properties of the produced vermicasts were assessed. The highest VS reduction (18%) occurred in dry solids of 15% and in a C/N ratio of 25 the maximum VS reduction was 17%. TKN decreased with increase in dry solids by the end of vermicomposting process, while the highest organic to mineral P reduction occurred in the dry solids of 15%. The results for different levels of C/N ratio showed that TKN and organic to mineral P of the worm-worked waste activated sludge decreased with increase in C/N ratio. The pH of the produced vermicompost in different levels of dry solids and C/N ratio increased in all the experiments.