Conventional methodologies have failed to provide vaccines against many widespread deadly human diseases, among them HIV, malaria and cancer. DNA vaccination has emerged as a powerful alternative approach for vaccines to a number of diseases. DNA vaccines have shown great promise in, in vitro systems, animal models, non-human primates and in human clinical trials, in inducing immune responses. Their use in human has not paralleled the superior therapeutic efficacy seen in the pre-clinical models. This review examines various strategies that have been used for improving non-viral DNA delivery. Non-viral vectors have come a long way since their initial use in, in vitro transfections, such as calcium phosphate and DEAE-dextran. The types of non-viral vectors range from lipids, synthetic polymers and peptides to microparticles. Particular attention will be paid to illustrate strategies that have been utilised to overcome intracellular barriers to effective gene delivery. The review will mainly discuss methodology in regard to DNA vaccines but the principles will be equally applicable to gene therapy. In addition we will review methods that have been used to optimise the immune responses observed when DNA vaccines such as use of cytokine or co-stimulatory molecule genes in addition to DNA coding for antigen. When these strategies are used collectively for the design of non-viral vectors, the dream of an ideal DNA vaccine may become closer to a reality.