Stream biota from different trophic levels may indicate different information about environmental conditions. We compared benthic diatoms and macroinvertebrates in relation to environmental variables at 81 stream sites in the John Day River Basin, Oregon. A total of 289 diatom species (80 after rare species were removed) and 190 macroinvertebrate OTU's (150 after rare taxa were removed) were recorded. The 5 most dominant diatom species were Achnanthidium minutissimum, Planothidium lanceolatum, Rhoicosphenia abbreviata, Cocconeis placentala and Navicula cryptotenella. The five most dominant macroinvertebrate taxa were Orthocladiinae, Oligochaeta, Diphetor hageni, Optioservus and Nematoda. Nonmetric Multidimensional Scaling (NMDS) was used to ordinate stream sites based on each assemblage. A Procrustes analysis showed that two ordinations of stream sites based on diatom and macroinvertebrate assemblages were significantly different (m² = .63, p<.001). However, both assemblages show strong correlations with environmental variables. Diatom assemblages were correlated with pH (r²=.38), conductivity (r²=.35), canopy cover (r²=.33) and total nitrogen (r²=.33). Macroinvertebrates were correlated with pH (r²=.39), conductivity (r²=.47), total nitrogen (r²=.36), canopy cover (r²=.50), %organic matter (r2=.40), %coarse gravel (r²=.37). The results suggest that primary producers respond to nutrient availability and light environment in streams while secondary consumers respond to both the variables which are important to the primary producers and stream reach habitat quality.