OBJECTIVES: To investigate the influence of unqualified samples on hospital operational efficiency and its economic impact, we analyzed the operation data and unqualified venous blood samples data from 9 domestic hospitals. METHODS: Data of 12914 unqualified venous blood samples were collected. The health economic cost of the unqualified samples was divided into 2 categories: the direct cost, which was the cost of consumables for re-collection; and the indirect cost, including the labor cost for re-collection and unqualified sample registering, the instrument downtime cost and the patient treatment cost due to re-collection. RESULTS: The re-collection rates of unqualified samples were different greatly because of the different sample rejection criteria among hospitals. For the re-collected samples, the average re-testing interval was 9.55 hours in outpatients while 5.91 hours in inpatients. The direct cost represented only 1.5% of the total cost. In the indirect cost category, the patient treatment cost was the highest, represented 92% of the total cost, labor cost was 5.3% and the instrument downtime cost was 1.2%. CONCLUSIONS: The unqualified samples would not only influence the quality of medical care and reduce the hospital operation efficiency, but also bring huge economic losses, which could be assessed by both the direct cost and the significant indirect cost subsequently.