Acute poisonings with carbon monoxide pose real challenge in the clinical toxicology. Its importance is determined both by high frequency of immediate life threatening conditions and by the risk of complications leading to permanent organs damage. The main objective of this study is an identification of prognostic factors on the base of analysis the cohort of patients hospitalized due to intoxication with these agents in the Toxicology Unit during the period 2006-2010. During the search process 571 patients hospitalized due to carbon monoxide poisoning during the period 2006-2010 were identified within total number of 21 400 subjects hospitalized during studied period. Therefore intoxications with carbon monoxide accounted for 2.66% of total admissions to the unit. The main sources of exposure were faulty gas heaters. Patients condition on admission varied, with most cases described as the moderate and severe state. At the moment of admission to hospital, the most frequently noted pathologies were: vertigo, headeache and complains from the respiratory tract. The most commonly encountered complication were labyrinths' injuries, neurological abnormalities and pneumonia. Mean concentration of COHb measured on admission in this group was in the blood 21.50 +/- 10.96%. Poor prognosis may be associated with such clinical features on admission, as: respiratory and circulatory disturbances, cerebral sequelae and reported sequelae from labyrinths. Such parameters as: COHb level, lactate and troponine concentrations and BE values measured on admission should be considered as the prognostic factors, determining the course of the disease and the outcomes of treatment.