INTRODUCTION: This study compared analytical and technical performance of Atellica UAS 800 and UAS 60 and assessed potential patient risks if results were not reviewed by laboratory personnel. MATERIALS AND METHODS: The study included 463 urine samples collected from February to March 2024, analyzed on both analyzers within 2 hours by two laboratory operators. Results from the UAS 800, recorded after operator review, were considered as the reference and compared to UAS 60 results obtained before and after review. Data were evaluated using weighted kappa (kappa ≥ 0.6 considered acceptable). Technical comparison was based on operator assessment. For risk analysis 23 errors and four severity levels were defined. RESULTS: After automatic image evaluation strong agreement was observed for calcium oxalate and yeasts (kappa: 0.83, 0.94), moderate agreement for red and white blood cells and epithelial cells (kappa: 0.75, 0.78, 0.75), weak agreement for bacteria, mucus and non-squamous epithelial cells (kappa: 0.57, 0.59, 0.40), and poorest agreement for hyaline and pathological casts and total crystals (kappa: 0.23, 0.07, 0.36). After review, kappa was acceptable for all parameters. Risk analysis identified 15 errors, with unrecognized total crystals and mucus being the most frequent (30.0%, 17.1%). Three errors were classified as intermediate risk (missing to report total crystal +1, mucus +1 and pathological casts ≥ +1), with none in high risk area. UAS 800 offers higher throughput and automatic sample aspiration, while UAS 60 uses manual aspiration. CONCLUSIONS: Atellica UAS 60 provides results comparable to UAS 800, quality of reported results remaining uncompromised even without operator review. It is suitable for low- to mid-volume laboratories and can serve as a backup in larger laboratories.