Materials and Methods: This study was a descriptive correlative investigation. Sampling among available samples and in the random form was done on 100 patients of CABG surgery with and without cardiopulmonary bypass in Madani Heart hospital, Tabriz, Iran in 2014. Data collection tool was a two- part questionnaire that included all demographic information and effective factors during intubation. These questionnaires were completed by a researcher beside the observation and written consent information contained in the patients’ records. Data recording was analysed using SPSS software.

Results: This study showed a significant difference (P < 0.05) in the duration of intubation and sternum openness. Also this study showed a significant difference (P < 0.05) in the duration of intubation and using cardiac pulmonary bypass.

Conclusion: This study showed that openness of the sternum and the use of cardiopulmonary bypass machine are crucial factors for increasing of duration of intubation of patients undergoing CABG surgery. So this group of patients was under mechanical ventilation longer than the others.