Microtubules are the largest filamentous components of the eukaryotic cytoskeleton. In spite of their extraordinary level of structural conservation, microtubules fulfill a vast range of different functions in cells. How this functional diversity is achieved remains an open question; however, recent advances point towards post-translational modifications (PTMs) of tubulin as a potent mechanism to generate microtubule identities. As many microtubule functions have direct implications for development and homeostasis of organisms, understanding the molecular functions of tubulin PTMs could provide a more differentiated view on the role of microtubules in both normal and pathological aspects of organism development.