Abstract: The present study was conducted to determine the effects of dietary heat killed Lactobacillus plantarum (HK L-137) on growth, survival, and immune response of juvenile striped catfish (Pangasianodon hypophthalmus). Feeding trial was carried out and four replicates groups of experimental fish (initial wt. 0.06 g) were fed with respective test diets containing four different concentrations of HK L-137 (0 ppm-control diet), 10 ppm, 20 ppm and 50 ppm, respectively.