Due to the fact of the continuous advances of medical technology, physicians are able to prolong life even in those patients who suffer from a terminal illness to whom no hope to recover from it is left. Frequently the use or not of different therapies on these type of patients is questioned, who demand the autonomy over the self person to decide the cessation of a treatment. That is why it was proposed to investigate on the opinions and attitudes on the omission or cessation of treatments which could prolong life (passive euthanasia) or active euthanasia in terminal patients. A survey, which preserved the confidentiality of patients, was done in which 1,109 individuals took part coming from three different sectors of the population: hospital health professionals (physicians n=346 and nurses n=346) from San Carlos University Hospital, Madrid; students (n=261) from Madrid Complutense University, and retired individuals (n=156) from an elderly people club located at the Madrid province (Pinto). Sample was formed by 40% of males and 60% of females, with ages between 20 and 90 years. Most of the surveyed people agreed in certain circumstances or totally agree with omission or cessation of drugs which could prolong life (passive euthanasia) in terminal patients (70%). Regarding active euthanasia more than half (55%) opposed to it, 34% agreed in certain circumstances and 10% agreed completely. Significant differences were detected (p<0.05) related to age, religious beliefs and political thoughts of the subjects. These results are compared to others already available.