The Pradhan Mantri Kisan Samman Nidhi (PM-KISAN) scheme, launched in 2018, aims to provide crucial financial support to farmers in India. This study analyses the constraints experienced by PM-KISAN recipients across five southern Indian states: Tamil Nadu, Andhra Pradesh, Telangana, Karnataka and Kerala. Data was gathered from 1,900 farmers through open-ended surveys, and the constraints were ranked using the Rank Based Quotient (RBQ) method. The top constraint, cited by 98.2% of farmers, was the inadequacy of the Rs. 6,000 annual payments, which was considered insufficient for meaningful agricultural investment. Other key issues included exclusion due to outdated land records (88.8%), ineligibility of tenant farmers (85.5%), irregular fund disbursement (75.4%), and a lack of awareness about the scheme's guidelines (70.5%). These findings indicate the need for policy reforms, including increasing the grant amount, revising eligibility criteria, and improving awareness and transparency in fund distribution. Addressing these issues could significantly improve the impact of the PM KISAN scheme, particularly for small and marginal farmers.