The design of primers has a major impact on the success of PCR in relation to the specificity and yield of the amplified product. Here, we introduce the applications of PCR as well as the definition and characteristics for PCR primer design. Recent primer design tools based on Primer3, along with several computational intelligence-based primer design methods which have been applied in primer design, are also reviewed. In addition, characteristics of population-based methods used in primer design are discussed in detail.