Dysfunctional affectivity is common in schizophrenia spectrum disorders (SSD), and may influence quality of life, illness progression and treatment effects. This study describes Positive (PA) and Negative (NA) affect and their relationship to demographic and clinical variables in 135 individuals with SSD. Affect dimensions were assessed by the Positive and Negative Affect Schedule (PANAS). Stepwise regression analyses with affects as dependent variables and demographic and clinical factors as independent variables were performed. Relative to healthy norms, the participants exhibited lower PA and a similar NA level. The PA score was not influenced by demographic or clinical variables. The NA score was predicted by a combination of male gender, single status, and items of general psychopathology from the Positive and Negative Syndrome Scale (PANSS). There was no relation between affects and classical schizophrenia symptoms. In conclusion, the SSD patients exhibited abnormally low PA. The affect level was not influenced by psychosis symptom severity, indicating that the PANAS is a relatively unbiased rating tool of affective responding in SSD. Finally, male gender, single status and general distress were modestly related to NA.