Abstract: Various embodiments of a system and method for integrated stowing and picking in a materials handling facility may include a process control component for monitoring processes within the materials handling facility in order to implement opportunistic picking and stowing. To implement an opportunistic pick, the process control component may determine that an agent has stowed a unit at a respective inventory location. The process control component may determine that the inventory location (or a nearby inventory location) includes a unit designated to be picked and may issue an instruction to opportunistically pick that unit. To implement an opportunistic stow, the process control component may determine that an agent has picked a unit from a respective inventory location. The process control component may determine that a conveyable receptacle utilized by the agent includes a unit that is designated to be stowed and may issue an instruction to opportunistically stow that unit.