The purpose of this study was to assess the extent to which citizenship and leadership training programmes influenced the physical fitness, social, emotional and adventure skills development of youths in Nigeria. The instrument used for data collection was the self-developed questionnaire. It consist of six sections on each the variable of youths development in physical fitness development, social fitness development, emotional fitness qualities, mental fitness attributes of youths development and adventure skills development of youths in Nigeria. This population for this study was drawn from students in secondary schools, Colleges of Education and Universities during the 2013/2014 academic session and the ex-post facto research design was used for this study. The purposive sampling technique was used to select the respondents according to their institutions and time of training at the centre. Using the random sampling technique, a total of 800 respondents were administered the questionnaire and only 707 representing 88.3% were duly filled and returned. The descriptive statistics of mean, standard deviation, percentage and the cumulative means were calculated for each item in each section of the questionnaire. The Pearson Product Moment Correlation (PPMC) statistic was used to analyze the data. The findings in the analysis revealed significant influence of citizenship and leadership training programmes on the indices of physical fitness attributes of youths who participated in the programme (p = 0. 000). The analysis also revealed that citizenship and leadership training programmes significantly influenced social behaviour patterns of youths (p = 0.000) Furthermore the results showed significant influenced of the training programmes on the emotional behaviour development, moral development and adventure skills development of youths in Nigeria (p = .000). Based on the results of this study, it was concluded that Citizenship and Leadership training programmes enhanced the development of physical fitness attributes of youths that included strength, muscular endurance, stamina and flexibility. It also improved social behaviour pattern of youths which was revealed by their enhanced self-confidence, patience and the ability to handle challenging tasks requiring emotional stability appropriately. It was further concluded that Citizenship and Leadership training programmes enabled the youths acquired critical thinking skills and knowledge for intellectual interaction. It was recommended that adequate provision should be made to stimulate and encourage researches on Citizenship and Leadership Training on youth development in Nigeria. Citizenship and Leadership Training should be made mandatory for all students in Secondary Schools and Tertiary Institutions in Nigeria.