Effect of starvation and refeeding on the structure of pyloric caeca was studied in the juveniles of Caspian Sea salmon. Juveniles (average body weight 12±0.1g) were subjected to four levels of feeding: full-fed for 6 weeks (FFF), 3 weeks fed and 3 weeks following starvation (FS), 3 weeks starved and 3 weeks fed (SF), and full-starved (SSS) for 6 weeks. Light microscopic studies showed significant reduction (p0.05) in the enterocytes height and number, villus length, epithelial area and pyloric caeca total area in starved groups as compared to control group. These reductions were more significant (p0.05) in long term starved group (SSS) than short term starved group (FS). Additionally, refeeding increased pyloric caeca size and enterocyte's number in SF group whereas, the epithelial total area and villus length did not reach the same area and length as control group. Results indicated that in Caspian Sea salmon juveniles food deprivation and consuming of food source, adversely affected the tissue of pyloric caeca while refeeding can be effective on healing tissue damage.