Soft-skill development is increasingly gaining importance in secondary education, and extra-curricular activities are an important component of the curriculum to develop them. The purpose of this study was to investigate the state and effectiveness of extracurricular activities (ECAs) in fostering the development of soft skills among students in a selected public secondary school in the Lushoto district of Tanzania. The study had two objectives, namely, to identify types of existing extracurricular activities in selected public secondary schools and to verify the availability of extracurricular activities’ facilities and infrastructure that would enhance the development of soft skills among students in the district. This study employed a mixed-methods research approach and a convergent design. We sampled a total of 298 respondents, including 276 students, 15 extracurricular activities teachers, 5 heads of school, and 2 ward education officers. The research tools included questionnaires, an interview guide, a focus group discussion, and an observation guide. The data was analysed through descriptive and thematic analysis. The findings revealed that the kinds of extracurricular activities practiced in visited secondary schools can be grouped into four categories, namely: sports and games; academic; production-related activities, including beekeeping and gardening; and social clubs. It was revealed that facilities and infrastructure for these activities were very limited. The study concluded that the kinds of extracurricular activities offered in the secondary schools in the district are inadequate for students, which leads them to complete secondary education without adequate soft skills for them to start an independent life. This leads them to fail to seize opportunities around them with the current high unemployment rate and turn to criminal behaviour. Extracurricular activities such as sports and games, debating clubs, farming activities, and subject clubs are important aspects in the development of a student and should be a priority for practice in public secondary schools nationwide. The implications of the findings for future curriculum reviews and school supervision are discussed.