C. elegans contains 25 Argonautes, of which, only ALG-1 and ALG-2 are known to interact with miRNAs. ALG-5 belongs to the AGO subfamily of Argonautes, which includes ALG-1 and ALG-2, but its role in small RNA pathways is unknown. We analyzed by high-throughput sequencing the small RNAs associated with ALG-5, ALG-1, and ALG-2. We show that ALG-5 interacts with a subset of miRNAs that overlaps with those bound by ALG-1 and ALG-2. alg-5 is expressed in the germline during oogenesis and is required for optimal fecundity. alg-5 mutants display modest changes in gene expression, including upregulation of genes involved in male development. Through an exhaustive analysis of ALG-5, ALG-1, and ALG-2 small RNA interactors, we identified only three new miRNAs, indicating that miRNA identification is nearly saturated in C. elegans. We also identified ALG-1 and ALG-2 associated small RNAs that do not resemble canonical miRNAs. Our results provide a near-comprehensive analysis of miRNA-Argonaute interactions in adult C. elegans and reveal distinct and overlapping roles for ALG-5, ALG-1, and ALG-2 in development, fecundity, and lifespan.