Understanding the interaction between habitat losses, environmental uncertainty, demographic stochasticity and genetics are the goal of population viability analysis. Minimum viable population (MVP) size is an estimate of the number of individuals of a species that will allow the continuation of the population into the foreseeable future. Here, we analyzed the population viability of Mato Grosso Antbird ( Cercomacra melanaria ), an endemic Thamnophilidae from Pantanal of Mato Grosso, Brazil. We focus on estimating the MVP. We used the program VORTEX to generate simulations for MVP based on demographic and environmental variables, including catastrophes, carrying capacity, reproduction and survival. We also used sensitivity analysis to determine which variables are most influential in viability. We conclude that the Mato Grosso Antbird has low chance to be extinction in the next 100 years under current conditions (quasi-extinction probability of 0.002). MVP of Mato Grosso Antbird is around 160 individuals. The most influential demographic parameter is the proportion of adult females that reproduce each year.