Background and Objectives: Respiratory distress syndrome is common in premature infants; frequency is inversely proportional to gestation and birth weight. RDS is mostly caused by surfactant deciency. For the diagnosis of RDS in newborns, the stable microbubble test on gastric aspirate and amniotic uid has been employed. The major goal of this study was to assess how well the stable microbubble test might predict RDS from oral aspirates of preterm babies. A prospective comparative study was Methodology: done on 73 inborn preterm neonates of AJIMS, Mangalore over the period of 18 months. Neonates with gestation <37weeks were included in the study. Oral sample was collected as soon as baby delivered. Stable microbubble test was done for all the babies, number of stable microbubbles were compared between newborns with RDS and newborns without RDS. Number of stable microbubbles were also compared with requirement of surfactant, use of CPAP and ventilator. The mean number of stable microbubbles i Results: n those with RDS was 17.77 SD ± 6.746 and in those without RDS was 31.14 SD ± 8.26. At a cut-off level of ≤25 microbubbles with Sensitivity 87%, specicity 78.57%, PPV 75% and NPV 89.2%. The ndings of our study suggest that sensitivity of chest x-ray in detecting RDS was 77.4%, specicity 92.86%. The negative and positive predictive value of chest x-ray in detecting RDS were 84.78% and 88.89% respectively. In comparison to Chest X ray in Conclusion: detection of RDS, stable microbubble test was found to be more sensitive at a cut off value of <25 stable microbubbles. However, specicity was found to be better with chest x-ray. Hence, stable microbubble test can be considered as a better screening test for RDS in preterm.