Due to current issues, necessary measures must be taken to face the likely of adopting nuclear energy. However, as time goes by, fewer sites are available and suitable for NPP development. Necessary steps must be taken now to identify and secure potential NPP sites. Thus, a study was jointly undertaken by TNBR and MNA to identify the various attributes and overall relative importance that will influence the suitability of potential NPP development sites in Peninsular Malaysia. A series of workshops were organized by MNA and TNBR, where a list of mandatory and rejection criteria were identified and used in producing the guideline. From this study, eight parameters were found to have profound effects on the ranking of potential NPP sites. For each parameter, various relevant sub-parameters and relative weightage were further listed out. Upon completion of this study, other siting related activities such as site identification, site screening and feasibility study can thus be undertaken immediately. The main purpose of this paper is to share the findings from this study.