Agri-food supply chains in developing economies are mainly driven by smallholder farmers. Price volatility driven by unpredictable supply-demand fluctuations, market speculation, and weak policy interventions significantly impacts farmers’ income, financial security and food security. Due to the lack of regulated market conditions and equal market access, farmers face critical challenges in revenue stability. This study analyzes the price dynamics of the vegetable supply chain in a developing economy by selecting representative vegetables that encompass diverse characteristics in terms of supply chain complexity and production patterns. The prices of these vegetables were analyzed using the time series feature evaluation, causal analysis with expert opinions and a cause analysis. The study identifies significant price fluctuations in these representative vegetables by employing time series feature evaluation techniques such as seasonal plots, trend analysis, decomposition, and autocorrelation functions. The causal analysis through expert opinions identified several underlying factors contributing to price fluctuations, which can be categorized under supply fluctuations, demand fluctuations, or external shocks. Following the causal analysis, a Five Why analysis was conducted to further investigate the causes that contribute to price volatility creating supply chain disruptions. The findings of the cause analysis emphasize the need for innovative digitalization-driven solutions to ensure food security by improving food availability, accessibility and affordability while safeguarding farmer livelihoods.