Delivery vehicles that are able to actively seek and precisely locate targeted tissues using concentration gradients of signaling molecules have hardly been explored. The directed movement toward specific cell types of cargo‐loaded polymeric nanomotors along a hydrogen peroxide concentration gradient (chemotaxis) is reported. Through self‐assembly, bowl‐shaped poly(ethylene glycol)‐b‐polystyrene nanomotors, or stomatocytes, were formed with platinum nanoparticles entrapped in the cavity while a model drug was encapsulated in the inner compartment. Directional movement of the stomatocytes in the presence of a fuel gradient (chemotaxis) was first demonstrated in both static and dynamic systems using glass channels and a microfluidic flow. The highly efficient response of these motors was subsequently shown by their directional and autonomous movement towards hydrogen peroxide secreting neutrophil cells. Chemotactic nanoparticles: Platinum‐loaded polystyrene nanoparticles were shown to exhibit directional movement along hydrogen peroxide gradients in both static and flowing systems. Furthermore, the nanoparticles could encapsulate the model cancer drug doxorubicin and migrate towards hydrogen peroxide producing neutrophil cells, suggesting such nanoparticles could be used as drug delivery vehicles.