The determination of antinuclear cytoplasmic antibodies (ANA) by indirect immunofluorescence provides very useful information in the approach to systemic autoimmune rheumatic diseases (SARD): the detection of ANA, their titer, and the patterns observed, as well as a negative result, can be of diagnostic and/or prognostic value. The main objective of this research was to evaluate the use of ANA in the approach to SARD, and the frequency and relevance of its request at the Hospital Interzonal General de Agudos “Dr. Oscar Alende” from Mar del Plata. The following frequencies were calculated: positive ANA, observed patterns, associated diagnoses, and medical services involved. Independence tests (Chi square) were performed to evaluate whether the titer depended on the presence of autoimmune disease and whether the presence of specific antibodies depended on the ANA titer. An ANA frequency of 55% was detected, with AC-4,5 patterns being the most frequent. It was found that the ANA titer depended on the presence of autoimmune disease and that the presence of specific antibodies depended on the ANA titer. Thirty eight percent of the reported diagnoses corresponded to SARD. The request for AAN was observed in a variety of other clinical contexts in which it is not indicated, mostly by medical services that are not specialised in autoimmunity, in detriment of its positive predictive value. To optimise the quality of the patient care process and assess the health economy involved, adequate training of the health team and interdisciplinary dialogue are essential.