This paper aims to describe and evaluate the results of the Nursing Quality Assurance (QA) Program in the Hospital de la Santa Creu i Sant Pau. The program was designed in 1987 as part of a global QA program involving all aspects of patients' care. The QA Program was organized at three levels: hospital, ward and joint medicalnursing. During the first 3 years of the study the following activities were carried out: (A) nursing process and results; (B) risk management; (C) patients' opinion; (D) utilization review; (E) ward nursing QA programs. Among other significant results, the program has detected that only 55.6% patients manifest that they sleep well at hospital, hygiene of dependent males (51%) is significantly worse than dependent females (81%) and patients' falls are more prevalent among oriented patients (73%) than disoriented patients (27%). Also a significative improvement has been demonstrated after implementing corrective measures in patients' information (7.5/10-8.1/10) and patients without supervision in emergency areas became from 35% to 0.02%. New nursing records were designed as a result of the QA assessment. The most important conclusion is that the Nursing QA Program is a valid instrument to evaluate general problems in the hospital and concrete problems in each ward.