Public distribution system (PDS) provides subsidised food grains through a network of fair price shops (FPS) to ensure food security for the poor people. PDS fraught is with many difficulties due to several constraints. Structural equation modelling (SEM) was applied to test the causal relationships between constraints and performance. A survey containing Likert-scale questions was conducted to collect data from 400 household who had been purchasing food grain from the PDS. Six constructs were identified in the study namely targeting error, information asymmetry, delivery mechanism, customer satisfaction, cost and performance. Results indicated that the existence of a statistically significant relationship among constructs. These findings suggest that the performance can be improved if some corrective measures are taken, i.e., to reduce cost and improve customer satisfaction in order to the realisation of the objective of ensuring food security for the poor.