The Ultra-Low Background Liquid Scintillation Counter developed by Pacific Northwest National Laboratory will expand the application of liquid scintillation counting by enabling lower detection limits and smaller sample volumes. By reducing the overall count rate of the background environment approximately 2 orders of magnitude below that of commercially available systems, backgrounds on the order of tens of counts per day over an energy range of ~3–3600keV can be realized. Initial test results of the ULB LSC show promising results for ultra-low background detection with liquid scintillation counting. •Observed background is within a factor of 2 of the predictions from simulation.•Background achieved is 2 orders of magnitude below commercially available systems.•Backgrounds are in tens of counts per day over an energy range of ~3– 3600keV.•Initial results show promise for ultra-low background detection with the ULB LSC.