OBJECTIVE To evaluate the impact and type of side-effects in patients treated with cetuximab and provide a description of the general measures and treatment. METHODS Retrospective safety study. We included all patients that received cetuximab from January to December 2009. All information was obtained from the Pharmacy and Oncology Department's Access databases and reviewed the patient's medical history. All data was registered in an Excel workbook. Skin toxicity was graded by the current National Cancer Institute-Common Toxicity Criteria (NCI-CTC). RESULTS During the study period 43 patients received treatment with cetuximab. Acneiform eruption was present in 30 of the cases (69.8%): 14 patients with grade 1 (48.3%), 13 with grade 2 (44.8%) and 3 with grade 3 (10.3%). These adverse effects appeared in a median of seven (4-28) days. In a median of 40 (20-56) days, ten patients (23.3%) presented xerosis, and three (7%) suffered painful fissures in hands and feet after a median of 28 (21-35) days. Paronychia was present in two patients after a median of 42 (35-49) days. Finally, an alteration in hair growth was observed in two patients with overgrowth of facial hair and one patient with overgrowth of the eyelashes. Five patients presented important conjunctivitis. Three infusion reactions occurred. A grade-based treatment algorithm was used for all patients that presented cutaneous toxicity. CONCLUSIONS A considerable number of patients treated with cetuximab develop dermatological side-effects which left untreated could represent a threat to the efficacy of the therapy. Therefore effective management is mandatory, patient education and immediate treatment based on a grade-based algorithm to alleviate symptoms is necessary, so that patient compliance is guaranteed.