The main purpose of this essay is to examine the effect of budget transparency on petty and grand corruption. To highlight the differences between the two measurements of corruption, and their relationship with budget transparency, the study will also make a comparison to a broader measurement of corruption. The research question for this essay is: Does budget transparency affect grand and petty corruption differently? Regression analysis is used to examine the relationship between budget transparency and corruption. The regressions are based on cross-section data from close to a hundred countries from all regions of the world. It is widely recognised that corruption is a difficult concept to measure. However, the study does find some interesting results. The initial bivariate regressions indicate that budget transparency is associated with lower levels of both petty and grand corruption, these are however not statistically significant. When controlling for democracy the coefficient for budget transparency is statistically significant for grand corruption, but not for petty corruption. The results also indicate that budget transparency generally has a stronger negative effect on grand corruption compared to petty corruption.