In order to investigate the combined action of temperature, humidity, and ultraviolet (UV) radiation, polyphenylene sulfide (PPS)-carbon fiber composite specimens were exposed to environmental degradation through two different techniques: water immersion and UV climatic chamber. The moisture weight gain curves of the composites were compared with those of the neat matrix in order to determine the interface effect on moisture absorption. Fourier-transform infrared spectroscopy of UV-weathered samples presented oxidation formation. Compressive tests and dynamic mechanical thermal analysis (DMA) revealed that the weathered materials gained in stiffness, nevertheless a small deterioration in strength was found after long periods of UV radiation exposure.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)