We conducted a meta-analysis of the available literature to assess the effect of decapod crustacean macroconsumers on the processing and invertebrate colonization of leaf detritus in streams. Supplementary methodological (experimental set-up), geographical (i.e. latitude, climate) and biological (i.e. macroconsumers body size, detritus quality expressed as initial C:N ratio) data were collected, with the aim of assessing their influence on effect sizes variability. Overall, our results indicated some important effects of decapod crustacean macroconsumers on both detritus processing and colonization by invertebrates. Among the different factors examined, detritus quality and macroconsumer body size were important for predicting detritus processing and invertebrate colonization effects, respectively. This indicates that the pivotal role played by decapod crustacean macroconsumers on leaf decomposition, food webs, and wider stream ecosystem functioning, may be regulated by the interplay of both detritus chemistry and consumer's body size. The limitations and inadequacies of the analyzed literature are discussed.