A study was carried out to evaluate the prospects of using marker assisted selection (MAS) in improving primary antibody response against Newcastle disease virus (NDV) vaccine and body weight in two Tanzania chicken ecotypes, namely Kuchi and Tanzania Medium (Medium). The study involved evaluation of the association between LEI0258 microsatellite alleles (a microsatellite located within the chicken Major Histocompatibility Complex) and primary antibody response and body weight. Results indicated that the allele 205 bp was significantly (P<0.001) positively associated with the elevated primary antibody responses against NDV vaccine, while the allele 307 bp was significantly (P<0.05) negatively associated with this trait. The allele 307 bp was also significantly (P<0.05) positively associated with body weight. However, based on the magnitude of R 2 (which were less than 0.10), it was envisaged that incorporation of these alleles into breeding programs would results into marginal response and hence their use in resource poor countries may sometimes not be justified. Therefore use of cheaper methods for the chicken MHC typing was recommended.