A Composite algorithm for improved image security is proposed by taking the advantages of DNA based image encryption and evolutionary algorithms (EA). A number of deoxyribonucleic acid (DNA) masks are created using logistic map function and DNA conversion rules. Then encryption is performed on the plain image to generate a number of cipher images. Finally, genetic algorithm (GA) is applied to find the best DNA mask. From the simulation results it is observed that the proposed scheme improves the level of security.