Background: The prolonged mechanical ventilation among cardiac surgery patients has been correlated with negative clinical outcome and increased healthcare resources utilization. The aim of this study was to identify the risk preoperative and intraoperative factors for increased ventilation among cardiac operated patients. Method and Material: An observational cohort study was carried out during a three-month period (from October 2010 to December 2010) among 48 consecutive patients who were admitted to the cardiac surgery intensive care unit of a general, tertiary hospital of Athens-Greece. A short questionnaire on basic socio-demographic characteristics and clinical patient data was attended. All patients had the same anesthetic and postoperative management. Statistical analysis was performed with SPSS version 16.0, using bivariate and multivariate linear regression. The p-value of ≤ 0.05 was considered as statistically significant. Results: The mean patient age was 64.7 (±13.7) years old, while the mean duration of intubation was 939 (±545) minutes. 67% of the sample was male. Multivariate linear regression analysis revealed that the older age [β coefficient 13.5, 95% confidence interval (CI) 2.7-24.2, p=0.015] and the increased duration of surgery (β coefficient 1.5, 95% CI 0.01-3.1, p=0.05) were the main risk factors for prolonged mechanical patient ventilation. Conclusions: The increased age and the prolonged duration of the surgery seem to be strongly associated with delayed tracheal extubation contributing to the early prediction of high risk patients for prolonged ventilation, a fact that could contribute to more effective allocation of the limited healthcare resources and better planning of the operative list.