Government budget reflects a prevision of future expenses and revenues which will predict the economic and financial situation of the country. This paper studies the effect of the publication, approval and actions inside the Portuguese government budget on the stock market performance of Portuguese companies. Additionally, the effects of presidential and legislative elections are also tested in the stock prices. The 46 companies represented in this study are listed on the Portuguese Stock Index between 1998 and 2013. I realize that a publication of government budget to the Parliament leads to a positive and significant return on the full sample results, basic materials and consumer services sector. The same sectors react in a positive way to periods of presidential elections. This study also provides a comparison between sectors. The consumer services sector reveals to be the more volatile sector before changes in the resources invested in each ministry. The consumer services sector is predominantly affected, in a negative way, by not rational expenses in the Ministry of Health. The financial sector has negative reactions on stock returns when the investment in the Ministry of Finance is reduced by the State
