The microencapsulation process has been increasingly applied in microorganisms in order to improve the shelf life of products. The objective of this work was to evaluate the effects of variables that are involved with the microencapsulation process of Trichoderma asperellum conidia, by spray drying, using maltodextrin DE20 as encapsulating agent. The colony-forming units and germination of the spores were determined before and after the microencapsulation process. The samples were characterized by moisture, germination and microencapsulation yield tests (MY). The variables that showed a significant effect (p≤0.05) for MY were: maltodextrin concentration and drying air velocity and the interaction between inlet temperature and drying air velocity. The moisture values (from 3.06 ± 0.843% to 8.13 ± 0.122%) were considered adequate for materials obtained by this technique. The percentages of viable conidia and MY of the treatments T2 (83.84a ± 1.41% and 75.20ab ± 1.38%), T5 (71.57b ± 2.5% and 85.74a ± 7.7%) and T7 (77.10 ± 1.51% and 81.67 ± 5.86%) have presented satisfactory results comparing with other studies. Therefore, the microencapsulation of conidia of Trichoderma asperellum by spray drying using maltodextrin DE20 showed to be viable for obtaining biological products.