Background: Cancer patients’ end-of-life care may involve complex decision-making processes. Colombia has regulations regarding palliative care and is the only Latin American country with legislation regarding euthanasia. We describe medical end-of-life decision-making practices among cancer patients in three Colombian hospitals.Methods: Attending physicians of 261 cancer patients in participating hospitals answered a questionnaire regarding end-of-life decisions: a.) decisions regarding the withdrawal or withholding of potentially life-prolonging medical treatments, b.) intensifying measures to alleviate pain or other symptoms with hastening of death as a potential side effect, and c.) the administration, supply or prescription of drugs with an explicit intention to hasten death. For each question addressing the first two decision types, we asked if the decision was (partially) made with the intention or consideration that it may hasten the patient’s death. Results: Decisions to withdraw potentially life-prolonging treatment were made for 112 (43%) patients, 16 of them (14%) with an intention to hasten death. For 198 patients (76%) there had been some decision to not initiate potentially life-prolonging treatment. Twenty-three percent of patients received palliative sedation, 97% of all patients received opioids. Six patients (2%) explicitly requested to actively hasten their death, for two of them their wish was fulfilled. In another six patients, medications were used with the explicit intention to hasten death without their explicit request. In 44% (n=114) of all cases, physicians did not know if their patient had any advance care directives, 26% (n=38) of physicians had spoken to the patient regarding the possibility of certain treatment decisions to hasten death where this applied. Conclusions: Decisions concerning the end of life were common for patients with cancer in three Colombian hospitals, including euthanasia and palliative sedation. Physicians and patients often fail to communicate about advance care directives and potentially life-shortening effects of treatment decisions. Specific end-of-life procedures, patients’ wishes and availability of palliative care should be further investigated.