The addition of surfactants has been shown to improve the enzymatic hydrolysis of lignocelluloses. The positive effects can be mainly attributed to the interaction of the surfactants with lignin at the substrate surface, which minimizes non-productive binding of cellulases to lignin, and enhances the accessibility of cellulose to cellulases. This study investigated the effects of surfactants on separate hydrolysis and fermentation (SHF) of steam exploded lodgepole pine (SELP) and ethanol pretreated lodgepole pine (EPLP). The addition of surfactant, Tween 80, during cellulase hydrolysis of SELP resulted in a significant increase in the cellulose-to-glucose yield. However, Tween 80 had little effect on improving the hydrolysis of EPLP. The addition of surfactant led to a substantial increase in the amount of free enzymes in the 48-hour hydrolysates of both SELP and EPLP. The effect of surfactant addition on final ethanol yield of simultaneous saccharification and fermentation (SSF) was also investigated by using SELP with added furfural and hydroxymethyl furfural (HMF).  The results showed that the surfactants did not have any effect on the consumption rates of furfural and HMF during SSF process by Saccharomyces cerevisiae. The presence of furfural and HMF at the experimental concentrations did not affect the final ethanol concentration either. The strategy of applying surfactants in cellulase recycling to reduce enzyme cost is presented.