Anxiety is the accompanying phenomenon of all stressful situations. Bo
ne marrow transplantation with uncertainty of its result and painfulne
ss of therapeutic procedures (cytostatic therapy, irradiation, inserti
on of catheter etc.) contributes to the development of anxiety. The pr
esent research evaluates denial as the dominant defence mechanism in p
atients treated with alogenous bone marrow transplantation. The result
s are analyzed as to the sex of the patients and the outcome of treatm
ent of a selected group of patients who suffered from acute leucose an
d underwent alogenous bone marrow transplantation. According to the fi
ndings, denial was their predominant defence mechanism. Also, a statis
tically significant difference in using denial was found between the p
atients who survived the transplantation procedure and those who did n
ot - in the second group denial was significantly more explicit in the
first few days of the treatment. These results might serve as a motiv
ation for similar researches in the future in order to achieve a more
successful outcome of the treatment of these patients.