After the fumigation of stock, grain stores may be resprayed regularly with a residual insecticide to lower the rate of insect reinfestation. For financial justification, respraying must result in a substantial delay in the need for refumigation. The costefficiency of respraying, for the protection of bagged milled rice, was investigated in six stores in East Java, Indonesia. All six stores were sprayed immediately after fumigation and then four were resprayed, at monthly intervals, with fenitrothion e.c. or w.p. Store reinfestation was monitored using bait‐bag traps and spear sampling, and the performance of the treatments assessed in the light of the calculated minimum delay to refumigation required for costeffective pest control. The major pest in all stores wasT.castaneumalthough other insects were present, especially Psocoptera. No substantial slowing of insect reinfestation was observed in the resprayed stores; the possible reasons for this are discussed. Thus neither of the respray treatments could be regarded as cost effective. Abandoning respraying of bagged milled rice stores might, at worst, result in a small increase in the frequency of fumigation but reliance on fumigation together with a single non‐residual spray treatment is likely to be a cheaper and more efficient option.