Turbulent benthic boundary layers generated by breaking of internal waves along the sloping bottom of a stratified lake play a significant role in vertical mixing. Benthic boundary mixing in density stratified lakes was investigated by conducting laboratory measurements. The turbulence characteristics of a benthic boundary layer were investigated by using MSCTI (Micro Scale Conductivity and Temperature Instrument) in conjunction with LDV (laser-Doppler-velocimetry). The measurements indicate that the dominant flux path, the path along which particles travel, is along the benthic boundary layer and then horizontally into the main water body via intrusions. The experimental measurements conducted in the Hydromechanics Laboratory at Purdue University suggest that the: (a) breaking of internal wave on sloping boundaries generates a turbulent benthic boundary layer; (b) the thickness of the boundary layer can be scaled as H ∼ (λωξL /(Ncosθ))(1/3); where λ, ω, ξ are internal wave length, frequency, and amplitude respectively, L is the length of the sloping boundary, N is the buoyancy frequency, and θ is the slope of the boundary; and (c) the turbulence intensity in the benthic boundary layer exhibits an oscillatory behavior. Copyright ASCE 2004.