This study analyzes the effect of public investment on monetary poverty in the department of Puno, Peru, during the period 2004–2015. According to the results obtained from the econometric estimations, it has been shown that public investment has positive effects in the reduction of monetary poverty; since on average for every 100 million soles executed in the previous period in investment projects public in the department of Puno, the poverty indicator will be reduced by 4.45%; evidence has also been found that public social investment has contributed the most to reducing poverty. On the other hand, it was found that public investment projects in sanitation, transportation, agriculture and energy were those that have contributed the most in reducing poverty.