Research on public knowledge about schizophrenia has so far examined various closed questions eliciting recognition-based knowledge rather than unprompted knowledge. We aim to explore the unprompted popular knowledge regarding causes and treatment of schizophrenia. In a representative survey conducted in Germany in 2001 (N = 5025), two open questions asked respondents to name possible causes and treatment options for schizophrenia. Answers were noted down verbatim and later grouped into categories. Psychosocial and biological causal explanations were equally predominant. Respondents recommended drug treatment more frequently than psychosocial measures like psychotherapy, and they mentioned a doctor's visit or a hospital stay most frequently as the adequate treatment setting. About 45% of respondents knew nothing about possible causes or treatments of schizophrenia. Hence, whereas those confidently naming causes or treatment options for schizophrenia favored professional medical treatment more than previously found, overall knowledge about schizophrenia has thus far been overestimated.