RecQ helicases have in recent years attracted increasing attention due to the important roles they play in maintaining genomic integrity, which is essential for the life of a cell and the survival of a species. Humans with mutations in RecQ homologues are cancer prone and suffer from premature aging. A great effort has therefore been made to understand the molecular mechanisms and the biological pathways, in which RecQ helicases are involved. It has become clear that these enzymes work in close concert with DNA topoisomerase III, and studies in both yeast and mammalian systems point to a role of the proteins in processes involving homologous recombination. In this review we discuss the genetic and biochemical evidence for possible functions of RecQ helicases and DNA topoisomerase III in multiple cellular processes such as DNA recombination, DNA replication, and cell cycle checkpoint control.