Psychiatric genetic research brings on the possibility of psychiatric genetic testing. The optimal and responsible utilization of genetic testing depends on knowledge of the potential consumers' attitudes and expectations regarding testing. The aim of this study was to assess potential consumers' attitudes and expectations toward psychiatric genetics and factors influencing their intentions to test. A questionnaire constructed to assess attitudes and intentions toward psychiatric genetic testing was mailed or given in person to individuals participating in different genetic studies aiming at identifying genes predisposing for mental illness. A total of 397 persons diagnosed with major depression, bipolar disorder, schizophrenia, or anxiety disorder participated in the survey. A large majority of the sample expressed an intention for themselves and their children to participate in psychiatric genetic testing. Support for prenatal testing was considerably less strong. A large minority expressed intention to test regardless of treatment possibilities. Intentions to test were positively associated with being a parent, trust in researchers, and expecting to feel better prepared for fighting the disorder when knowing of the presence of risk genes. Intentions were negatively associated with the fear of psychiatric genetic research bringing on too many difficult choices and fearing not to be able to cope with the results of a psychiatric genetic test. These results indicate that psychiatric genetic testing is not just perceived as a way to better treatment. Other expectations may motivate testing even though the clinical validity of the test is poor.