The morphology and developmental stages of Misotermes mindeni Disney & Neoh (Diptera: Phoridae), a newly described endoparasitoid of the fungus-growing termite Macrotermes gilvus (Hagen) (Termitidae: Macrotermitinae) were studied, and biometric descriptors of eggs, larvae, and pupae were recorded. The larvae of M. mindeni exhibit three larval stages. Larvae complete their first instar development in fourth larval instars and major presoldiers, whereas the second and third instars develop entirely in major soldiers' head capsule and abdomen, respectively. The second instar can be readily differentiated from the first by the presence of a posterior spiracular base and more defined body segments, and the third instar can be discriminated from the second by the presence of respiratory horns and a well-developed posterior spiracular base. Differentiation of the larval instars is further supported by morphometric measurements. The first instar moves freely within the host's body cavity and head capsule, whereas the last two instars remain in the host's head capsule and abdomen, respectively. Termite developmental stages were used as a model to determine the developmental time of M. mindeni larvae. Duration between the first and second instars was 19.00 ± 2.28 d and between second and third instars was 36.88 ± 5.17 d. It took the third instar, 0.53 ± 0.08 d to reach pupation. The pupal stage lasted for an average of 13.51 ± 0.74 d. Mean adult longevity was 1.47 ± 0.57 d and 3.00 ± 0.98 d for females and males, respectively. Longevity of males was significantly longer than that of females.