The first global case of government-commissioned deliberative polling (DP) for developing the Strategy for Innovative Energy and Environment was held in August 2012. In the following October, we investigated the public evaluation of the policymaking process, focusing on the standpoint of citizens’ perception of procedural fairness. We also explored the effects of procedural fairness of both DP and “Public Debates” on the social acceptance of the strategy, including DP, the public debate process, trust in the government, and the pros and cons of nuclear electric power generation. We administered an online survey to 2,000 Japanese residents. The findings were as follows: (a) the main determinants for procedural fairness in DP were “extent of deliberations” and “diversity and comprehensiveness of panel of experts”; (b) the main determinants for procedural fairness in “Public Debates” were “reflection of the policy” and “information disclosure”; (c) that of “procedural fairness evaluation in ‘Public Debates,’ ” “DP,” and “trust in the government” promoted public acceptance of the strategy. We discussed the importance of procedural fairness in environmental policymaking; public acceptance of a policy is not only affected by the procedural fairness for the entire citizen participation process, but also by each type of citizen participation.