Bronchoalveolar lavage (BAL) is a widely used clinical and research tool even though certain steps in the procedure have not been standarized. One step that is subject to variation is the technique used to instill and recover BAL fluid. Our aim was to assess whether attaching a plastic tube between the syringe and the working channel of the flexible bronchoscope allowed recovery of more fluid in comparison with recovery using only a syringe, and whether tubing had a favorable impact on diagnostic yield and complications. A randomized multicenter study was performed in eleven public hospitals in Catalonia (Spain). Patients scheduled for BAL were randomly assigned to tubing (n=140) or no-tubing groups (n=155). Flexible bronchoscopy and a 150 mL BAL in three 50 mL aliquots with or without tubing attached to the syringe. In the group with tubing, 8% more fluid was recovered. The difference was both statistically significant and clinically relevant given that 17.4% more diagnoses, 6.9% fewer complications, and 8.8% fewer technical failures were recorded. Based on these results, we recommend performing BAL using plastic tubing between the 50 mL syringe and the working channel of the flexible bronchoscope when carrying out manual instillation and suction.