Temporomandibular disorder (TMD) encompasses a set of disorders involving the masticatory muscles, the temporomandibular joint and associated structures. It is a complex biopsychosocial disorder with several triggering, predisposing and perpetuating factors. In the etiology of TMD, oral parafunctions, namely bruxism, play a relevant role. The study of bruxism is complicated by some taxonomic and diagnostic aspects that have prevented achieving an acceptable standardization of diagnosis. The aim of this study was to analyze the prevalence of temporomandibular disorders and bruxism in a Portuguese sample.