QTc prolongation is associated with the administration of some antipsychotics but the QTc interval is also known to vary physiologically. There is little published evidence about changes in QTc variability during treatment with antipsychotics. In this prospective investigation, we analyzed ECGs in 61 patients suffering from a schizophrenic disorder who were treated with different antipsychotics and 31 sex- and age-matched healthy controls. We found no differences in QTc intervals nor in QTc variability between patients and controls. Our results raise the question of the clinical relevance of a single ECG for diagnostics of cardiac complications in schizophrenia patients and suggest the need to conduct ECG monitoring in patients at high risk for cardiac complications during antipsychotic treatment.