Objective: Schizotypal personality disorder, a schizophrenia spectrum disorder and schizotypal features share common genetic etiological and pathophysiological factors with schizophrenia. The severity of schizotypy has to be evaluated by standard measures in the studies examining the neurobiology and genetic background of schizophrenia and schizotypal personality disorder. The Schedule for Schizotypal Personalities (SSP), a structured interview which consists of ten scales, provides a detailed evaluation and gradation of several features of schizotypal personality disorder. The aim of this study is to adapt the SSP in Turkish language and to investigate its psychometric properties. Methods: Twenty-one patients diagnosed with DSM-IV schizotypal personality disorder, were evaluated by three independent raters in joint interviews, in order to examine the inter-rater reliability (intra-class coefficients) and internal consistency of the schedule. The association of the scaled scores with age and gender was also assessed. Results: Inter-rater reliability coefficients for ten scales of the schedule, ranged from 0.80 and 0.97. The schedule had a high level of internal consistency; Cronbach's alpha for the first rater was 0.76. Age was found to be correlated with certain scales (7 and 8), but no difference was found with regard to gender. Conclusion: Inter-rater reliability and internal consistency of the schedule were acceptable and Turkish version of it can be used in the schizophrenia and schizoypy research. (Anatolian Journal of Psychiatry 2010; 11:313-320).