This study investigated the level of environmental citizenship development through curriculum development planning among primary school pupils in Rivers State. Three research questions and two hypotheses guided the study. The descriptive survey design was used. The population for the study was the 15,611 teachers in the 962 public primary schools in Rivers State. A stratified random sampling technique was used to draw a sample of 1,600 teachers which represents 10.2% of the population. A researchers' designed questionnaire titled "Curriculum Development Planning in Environmental Education Questionnaire" was the instrument used for the study. The instruments were validated by three experts. Reliability coefficients of 0.88 (Curriculum Provision), 0.73 (Environmental Education Projects), and 0.79 (Challenges) were derived using Cronbach alpha. Mean and standard deviation was used to answer the research questions while the hypotheses were tested using the z-test. Findings revealed that the extent to which environmental education projects were utilized to develop environmental citizenship in pupils is low. The challenges militating against the teaching of environmental education are lack of commitment from the school management, lack of time in the lesson timetable to integrate environmental education contents in other subject areas, and teachers' inadequate knowledge of environmental education integration techniques. It was recommended amongst others that the Nigerian Education Research and Development Council should design age-appropriate curriculum contents/topics that can be integrated into various subjects