We contribute to the very incipient literature that estimates the intergenerational mobility of income from large-scale administrative data using high-quality income data and provide novel evidence of intergenerational income mobility in a middle-income country, Uruguay. Our estimates address the important role of informal labor markets, one of the features of low- and middle-income countries, and a major challenge to obtain unbiased estimates of intergenerational mobility in these countries. We estimate an IRA of 0.292, indicating that persistence is higher in Uruguay than in high-income countries, but lower than in the US. Our results show that (i) informal income increases intergenerational persistence, (ii) intergenerational persistence is higher at the upper half of the distribution, especially at the richest decile, and (iii) intergenerational income persistence is largest among parents and children of the same sex.