Stonefly density, biomass, size and diversity relationships with CPOM and FPOM were elucidated from 12 months of Surber sampling in a riffle of a 2nd order, northeastern Oklahoma stream in 1983–84. Samples taken across an observable gradient of allochthonous leaf material resulted in clumped CPOM distributions in monthly samples (n = 10)for 10 of 12 months. FPOM was regularly distributed among monthly samples. There was an inverse relationship between CPOM an d FPOM for most months suggesting substratu m interaction in organic matter retention. Mean annual density of 8 stonefly species was 113 ± 150/0.1 m2. Nymphs were found in clumped distributions for 11 of 12 months (p < 0.05). Density, biomass and diversity were positively correlated to CPOM annually. Autecolo‐gical analysis of 8 species showed varying degrees of association with CPOM and/or FPOM, suggesting specific habitat preference, ontogenetic shifts, or possible biotic interaction. Density and biomass of 4 species was related to CPOM (Acroneuria evoluta, predator;Isoperla namata, generalist;Amphinemura delosaandProstoia completa, shredders). These species contributed 72.5% of the total stonefly biomass sampled (13.39 gm. dry wt.). CPOM provides both food and habitat for stoneflies, and is therefore important in their community structure and function.