Introduction: Detection of antinuclear antibody (ANA) by immunofluorescence assay (IFA) is the method of choice for screening autoimmune polyarthritis, where the different patterns are etched in the cellular components as per the group of antibodies present in the patient. Like all other screening tests, it has its sensitivity and specificity, and the final confirmation is done by doing a multispot immunoblot testing, where the specific antibodies against a specific antigen is detected. Aims and objectives: The study aimed at finding out the sensitivity and specificity of IFA with respect to immunoblot assay and to detect whether any pattern can be detected to attribute to false-positive and false-negative cases. Materials and methods: The conducted study is a retrospective analysis of 100 reports available from the Laboratory Information System. Patients referred by rheumatologists with clinical polyarthritis prescribed for both ANA by IFA and immunoblot are taken for the study. Sensitivity and specificity of ANA by IFA is calculated taking immunoblot as confirmatory gold standard. Results: The sensitivity and specificity were calculated as 80 and 84.3%, respectively, in polyarthritis cases and anticell (AC)-1 and AC-4 were implicated in most of the false-positive and false-negative cases. Conclusion: Antinuclear antibody by IFA needs confirmation by immunoblot for antibody profile characterization. AC-1 and AC-4 if detected on IFA mandates for immunoblot as most of the false positives and negatives are implicated with these patterns.