Adverse effects induced by cytotoxic chemotherapy (CT) have been mostly evaluated in clinical trials. The aim of this study was to assess in a nonselected patients group the incidence of CT-related toxicities and to identify risk factors in daily practice. Patients treated with CT (except cisplatin-based or carboplatin-based CT), for a solid tumour, were included in a prospective multicentre observational study. Clinical parameters, renal function and albumin level were assessed at baseline. Multivariate logistic regression was used to identify risk factors of CT-related toxicities. A total of 502 patients were recruited in different types of oncology departments. During CT, 62% of patients experienced grade 2-4 toxicities. Haematological toxicities affected 34% of patients and 20% of patients developed an infection requiring antibiotics. For 55% of patients, toxicities induced dose reduction (59% of cases), CT delay (25%) or discontinuation (16%) according to the management habits in the investigating centre. Performance status≥1, breast cancer, lymphopenia, hypoalbuminaemia and clearance creatinine<60 ml/min were risk factors for haematological toxicity. Performance status≥1, hypoalbuminaemia, proteinuria and clearance creatinine<90 ml/min were risk factors for change of CT schedule. A majority of patients receiving CT experienced significant toxicity leading to change of standard CT protocol. Albumin, creatinine clearance and lymphocyte should be routinely monitored at baseline to manage CT and to prevent their toxicities.