Our objective is to establish whether the level of assets, liabilities, and income diversification of the Mexican banks is related to their profitability and risk levels. Using the financial information of the 15 key banks, between 2010 and 2021, along with the Herfindahl-Hirschman Index and a series of polynomial regression analyzes, we calculated the diversification level of each bank. We also computed a series of inflection points suggesting that Mexican banks need to adopt an asset specialization long-term strategy, but to a point because a radical transformation would be detrimental to both return and risk. Similarly, we do not recommend venturing into a radical income diversification strategy, for the same reason. On the other hand, the liability diversification strategy is difficult to apply for achieving the mentioned objectives. Furthermore, we would like to emphasize that our analysis takes into consideration the high presence of foreign banking affiliates in Mexico.