High concentrations of inorganic N and P have been reported in overland/litter interflow. This suggests nutrients are derived from the forest floor O-horizons, and there has been little biological uptake or contact with the mineral soil where strong retention would be expected. Forest floor monoliths (0.6 m x 2.4 m) consisting of the combined Oe and Oi horizons were collected near South Shore Lake Tahoe, Nevada, for greenhouse leaching experiments. Three monoliths were left intact, and three were hand separated according to horizon for a total of 3 treatments (combined Oe and Oi, Oe only, and Oi only) by 3 replications. Samples were randomized and placed into lined leaching bins. Initial leaching consisted of misting at a rate of 0.05 cm/min for 5 min at 30 min intervals over 3 hours to simulate typical early fall precipitation. This was followed by cycles of daily snow applications (2.5-3.5 cm water equivalent each), and a final misting to simulate spring precipitation. Leachate was collected, analyzed for NH4+-N, NO3--N, and ortho-P, and a nutrient balance was computed. Measured concentrations of ortho-P in the leachate were as high as 5.0 mg L-1, three orders of magnitude greater than those commonly reported for tributaries of the Lake Tahoe Basin. Although peak concentrations of up to 0.5 mg L-1 NH4+-N and NO3--N were found, these were not as high as anticipated based on data collected in-situ. There was a net retention of NH4+-N for all treatments, but a net release of both NO3--N, and ortho-P. Total contributions (mg) of N and P were highest from the Oe and Oe /Oi combined treatments, but when expressed as per unit mass significantly (p<0.05) higher amounts were derived from the Oi materials. Forest floor leachate appears a significant source of biologically available N and P.