In the arboretum of Universidad Nacional de Colombia sede Medellín, Cassia fistula (Golden Shower Tree) and Leucaena leucocephala (Leucaena) exhibited early defoliation. Erysiphe quercicola and Telimena canafistulae, associated with powdery mildew and tar spot, respectively, on C. fistula, were identified using morphological and molecular techniques, both representing new records of fungi for Colombia. Similarly, Phyllactinia leucaenae was proposed as a new combination for Ovulariopsis leucaenae and was associated with powdery mildew on L. leucocephala, which to the best of our knowledge is another new record for Colombia.