Capgras` syndrome, also known as negative imposter syndrome, is a psychic condition where a person believes that someone they know has been replaced by an imposter. It is the most common delusional misidentification syndrome(DMS) that is often underdiagnosed in practice because it is often shrouded by other mental health issues with which it is concurrent. Capgras` syndrome is named after the French psychiatrist Joseph Capgras who first diagnosed this syndrome in cooperation with his colleague Jean Reboul-Lachaux in 1923. This is one of the many syndromes classified as paranoid misidentification syndromes. The cause of this syndrome is not entirely known and is possibly linked to many other diseases. This article presents the symptoms, possible causes, existing treatments and some illustrative clinical cases of the Capgras` syndrome.