Abstract.A simple and reliable method for rapid and selective separation of trace amounts of Sr2+ ions from alkali and alkaline earth metal ions by using octadecyl silica membrane disks modified with decyl- 18-crown-6 in the presence of 1.0103M picric acid is presented. The influence of picric acid concentration, flow rates and nature and amount of the stripping acid have been investigated. Maximum capacity of the membrane disks modified with 10mg of the macrocycle was found to be 484g of Sr2+ ions. The proposed method permitted enrichment factors of about 80 and higher. The limit of detection of the proposed method is 1.5g per 1000ml. The method was successfully applied to the recovery of Sr2+ ions from different synthetic and water samples.