Taking into account the physical-chemical characteristics of the SC-OFMSW processed at Valorsul's anaerobic digestion plant, the influence of seasonal effects was studied. The waste presents a good quality, with a putrescible content of around 90%. In terms of chemical characteristics, the waste composition is similar to the one referred in the literature. The results show that seasonal variations seem not to affect the SC-OFMSW characteristics. The waste is very soluble and for that reason the solids content in the digester is low (TS in the digestor is 2.8%). The production of biogas is higher than the one predicted in the design operational parameters. Consequently, smaller quantities of compost are produced.