Abstract Background The 20-item Subjective Well-Being Under Neuroleptic Treatment Scale (SWN-20) is a self-report scale developed in order to assess the well-being of patients receiving antipsychotic medication independent of the improvement in their psychotic symptoms. The current study reports on the reliability and the psychometric properties of the Greek translation of the SWN-20. Methods A total of 100 inpatients or outpatients with schizophrenia (79 males and 21 females, aged 42.6 ± 11.35 years old) from 3 different facilities were assessed with the Positive and Negative Symptoms Scale (PANSS), the Calgary Depression Scale and the Simpson-Angus Scale, and completed the SWN-20. The statistical analysis included the calculation of Pearson product moment correlation coefficient, the Cronbach α and factor analysis with Varimax normalised rotation. Results The SWN-20 had an α value equal to 0.79 and all the items were equal. The factor analysis revealed the presence of seven factors explaining 66% of total variance. The correlation matrix revealed a moderate relationship of the SWN-20 and its factors with the PANSS-Negative (PANSS-N), PANSS-General Psychopathology (PANSS-G), the Simpson-Angus and the Calgary scales, and no relationship to age, education and income class. Discussion The Greek translation of the SWN-20 is reliable, with psychometric properties close to the original scale.