The Public Participation Process (PPP) for Environmental Assessment (EA) is a mandatory procedure to facilitate participation of Interested and Affected Parties (IAAPs) in decision making for proposed development projects. Participation of the vulnerable IAAPs in the PPP is affected by complex challenges. This study investigated the nature and impact of the challenges in the decision making process. Five key challenges: lack of EA legislation awareness; imbalanced power relations; negative past experience; threat to environmental autonomy; and poor project planning affected the PPP cases were analysed in this study. These challenges emanate from internal and external environmental factors. The study maintains that a good understanding of potential challenges associated with development project sites will enable EAPs to design better and more responsive PPP approaches. To achieve this, the study recommends a Dual Approach Planning Model (DAPM). This approach recommends designing the PPP through pre-planning information appraisal and prediction of potential challenges to create awareness about potential challenges.