In cases when mother’s milk is not available to a great ape infant (e.g., rejection), zoo nutritionists/veterinarians are responsible for formulating a milk replacer to maximize the chances of survival of the neonate. To accomplish this, they generally use milk from commercially available species (e.g., cow and goat) as well as nutritional supplements and other additives. As is the case in humans, placental transfer of immunoglobulin (Ig)A occurs throughout pregnancy in the gorilla. After birth, neonates rely solely on nutrients and Igs via the mother’s milk until approximately 5 mo of age and are weaned at 3 to 4 years of age. Unfortunately, there is currently no useful information regarding the IgA profile of milk and how stage of lactation alters IgA concentration in gorilla milk. The objective of this study was to identify the pattern of IgA concentrations in milk from gorillas throughout lactation. Milk samples from 4 gorillas were collected between January 2009 and October 2014 and stored at −80°C until further analysis. Concentrations of IgA in milk were measured using a Human IgA ELISA kit. Data were grouped according to month in milk (MIM; 0 < MIM = 5, 5 < MIM = 10, 10 < MIM = 15, 15 < MIM = 36, and MIM >36). The data were analyzed as a complete randomized design with gorilla nested within MIM as a random term and MIM as a fixed effect. Month in milk had a significant (P < 0.01) affect IgA concentrations. Concentrations of IgA were highest for MIM >36 (81.3 µg/mL) followed by 0 < MIM = 5 (53.9 µg/mL). The increase in concentrations of IgA in later lactation may reflect reductions in milk production and this warrants further investigation. Results from this study provided a better understanding of the IgA profile of milk from gorillas. Additional knowledge regarding fluctuations of other immunoglobulins as well as nutritional profiles in gorilla milk will assist professionals charged with their care in captivity to develop improved hand-rearing protocols.