Tracheobronchial suctioning using the closed suctioning system (CSS) has physiological benefits for critically ill patients. Despite these benefits, nurses have raised concerns about the CSS. The aims of this study were to identify concerns, count how frequently they occurred and examine the relationship between the concerns and the experience of the operators. Experience was defined as length of time working in an intensive care unit (ICU) and length of time using the CSS. Using a field research approach, six major concerns were identified: showering of condensate from the flush port over the hands of staff; difficulty cleansing the inner tube after use; ineffective secretion removal; disconnecting the CSS to use conventional catheters; 'sticking' of the CSS in the endotracheal tube; and possible tracheal trauma as observed by blood stained secretions. Based on these findings, a data collection form was developed and over an 8-week period, 75 staff completed 923 forms. The findings indicated that although these concerns occurred frequently (up to 66% of the time), there was no relationship between their frequency and the experience of the operator. The study concludes that, if used appropriately, the advantages of CSS outweigh the disadvantages. Policies and guidelines should be developed to redress issues of secretion removal and infection risks to maximize effectiveness of the CSS for critically ill patients.