Leaf litter decomposition and associated macroinvertebrate communities were compared in leaf packs across forest streams in clearcut (n=9) and undisturbed (n=12) low-order watersheds on the Canadian Shield. Clearcut watersheds were recently logged under best management practices including 30-100m wide no-cut buffer zones. No differences between logged and reference sites were detected for any of the reach- and catchment-level characteristics (except % area logged) or any water quality parameters measured. Leaf decomposition in coarse-mesh packs was significantly lower at logged sites. A step-wise multiple regression model of mass loss on 15 reach- and catchment-level characteristics indicated that only logging presence/absence (r = -0.524) and average reach velocity (r = 0.397) were significantly and independently associated with leaf litter decomposition. Macroinvertebrate taxonomic richness was significantly lower in logged streams. A multivariate ordination and analysis of similarity separated logged from reference streams, and abundances of the 3 most discriminating taxa were significantly lower at logged than at reference streams. Leaf-litter decomposition and aquatic macroinvertebrate community structure were successful bioindicators of catchment logging impacts, even when logging was conducted under best management practices. Effects on litter decomposition and leaf-pack macroinvertebrate communities were linked to upland logging disturbances because riparian areas were intact.