Introduction: Neonatal jaundice is one of the most common reasons for hospital admission in low resource settings. Treatment is frequently inadequate as conventional phototherapy requires frequent bulb changes. LED phototherapy has comparable efficacy to conventional phototherapy, and the bulbs last over 40,000 hours. This observational study compares the effectiveness of three LED machines, two single-sided and one double-sided in routine use in Vietnam. Methods: We included all infants weighting 1500g and with jaundice diagnosed visually or by Total Serum Bilirubin (TSB) measurement at The Da Nang Hospital for Women and Children (Da Nang, Vietnam). The primary endpoint was the average hourly change in TSB over the first six hours of treatment. The secondary endpoints were duration of treatment; average hourly change in TSB over treatment, and length of stay in the neonatal unit. Multivariable analysis and bootstrap methods was performed to compare outcomes, adjusting for potential confounders. Results: All outcomes were comparable in the two single-sided machines. The double-sided machine showed 54% increase in the hourly speed of TSB reduction (1.3 μmol/L/hr, 95% CI 0.3-2.3), with a 45% increase in the speed of TSB reduction over the duration of treatment (0.9 μmol/ L/hr, 95% CI 0.6-1.3). In addition, the double-sided machine was associated with 21% reduction in the duration of treatment (14 hours, 95% CI 5-22) and 16% reduction of length of stay (14 hours, 95% CI 3-25). Conclusion: The results confirm and quantify the benefits of increasing surface-area exposure during phototherapy. Adjusted for multiple potential confounders, use of double-sided phototherapy can substantially increase the speed of TSB reduction, and substantially decrease the duration of treatment and length of stay in the NCU.