Depression is a common complication of stroke. Reported prevalence ranges from 23 to 40% of patients with stroke. The range is very wide, because there are methodological differences between the different studies (e.g. diagnostic criteria, type of rating scales used, timing of evaluation and wide range of patient selection). Poststroke depression (PSD) has a negative impact on functional recovery, activities of daily living (ADL), and quality of life, and can impede the process of rehabilitation. Furthermore, PSD leads to increased morbidity and mortality. It is therefore important to identify and treat depression in its early stages. In this paper, we reviewed the diagnosis and treatment of PSD. Many studies used diagnostic tools that are routinely employed for the diagnosis of major depression and other depressive disorders. Diagnosis is hindered by problems related with self-reporting in patients with cognitive and communicative deficits following stroke, and is confounded by the fact that many of the somatic symptoms of depression can also arise directly from stroke itself. There is therefore a concern about the validity of regular diagnostic tools in assessing poststroke patients. Different approaches and diagnostic criteria used to assess neuropsychiatric disorders in different studies make it difficult to compare their results and to interpret neuropsychiatric phenomena. The effects of treatment of poststroke depression have been examined and confirmed in several trials with tricyclic antidepressants and selective serotonin reuptake inhibitors (SSRI). There is currently no evidence that exercise, whose effectiveness has been demonstrated in major depression, may reduce depression in stroke patients. This is an area to be further explored in rehabilitation settings.