In Brazil, the vast experience and ability for agribusiness generate reflections regarding implications of fiscal and agricultural policies on the food pricing and, consequently, on food security. Thus, this study aims to evaluate the impact of the Minimum Price Policy for Agriculture, rural credit and indirect taxes on prices of some of the more important food from the Food Basket of Porto Alegre (RS), Brazil. To this end, descriptive and inferential statistics were used to identify causal relationships between variables in the period from January/2005 to April/2011. It was observed that multiple linear regressions were statistically significant, except those estimated for coffee and wheat flour prices. Besides, the supply of products sampled tends to be elastic, considering the positive relationship between food prices and the proxies of public subsidies for agricultural production and marketing. It was perceived that changes in indirect taxes on consumption imply variations in the same direction in prices of rice, beans, milk, oil and bread. Thus, it is worth noting that the encumbrance of essential food can hamper economic access to food in the area studied. Finally, considering the moderate degree of linear association between the explanatory variables and food prices, it is suggested that these variations can also be explained by factors related directly to the productive and competitive process.