Goals of work Cancer patients often experience distress. However, the majority of newly diagnosed patients gradually adapt to the crisis. When symptoms of distress and anxiety persist over months, patients require psychosocial support. The aim of the present study was to determine the proportion of cancer patients who indicate the need for psychosocial support and to identify sociodemographic, psychological and illness-related factors predicting the need for psychosocial support in a German sample. Materials and methods The cross-sectional retrospective study was administered to 710 cancer patients who had been inpatients at the University Hospital of Cologne. The response rate was 49.5%. Patients suffering from bronchial, oesophageal, colorectal, breast, prostate and skin cancer participated in the study. The severity of depressive symptoms was assessed using the German version of the Major Depression Inventory. The level of anxiety was assessed with the state subscale of the German version of the State-Trait Anxiety Inventory. To measure the functional aspects of health-related quality of life, the scales “physical functioning”, “role functioning”, “emotional functioning”, “cognitive functioning” and “role functioning” of the European Organisation for Research and Treatment of Cancer QLQ-C30 Questionnaire (EORTC QLQ-C30) were used. Main results Of the cancer patients, 18.9% indicate an unmet need for psychosocial support and 9.5% are actually using psychosocial services. In a multiple logistic regression, significant indicators of the need for psychosocial support are gender p  = 0.014; standardised effect coefficient (sc) = 1.615 and emotional functioning ( p  < 0.001; sc = 1.533). The estimated model has a specificity of 92.2% and a sensitivity of 54.0%. Conclusion Almost a third of the cancer patient population indicates an unmet need for psychosocial support or is actually using psychosocial services. Emotional functioning is a central predictor of the requirement for psychosocial support. Women are emotionally more affected than men and need more psychosocial support. The prognostic validity of the severity of depression and anxiety is limited.