The breeding biology of Small Bee-eater Merops orientalis was studied in Nagapattinam District of Mannampandal, Tamil Nadu, India between 2005 and 2006. A total of 34 nests were studied and the bee-eaters were found to excavate long tunnels ranging in length from 79 to 125cm (104.9±123.48 cm) and ending in widened egg chambers. The mean diameter and circumference of the entrance hole opening was 8.94±1.03 cm and 26.9±3.55 cm respectively. They excavated nest holes at a mean height of 52.1±2.69 cm from the bottom and 158.7±4.11 cm from the top of sandy river banks. The clutch size varied from 3 to 6 with a mean of 3.5±0.88 and clutches of three were very common. The egg dimensions ranged between 23.0 x 20.0 mm and 18.0 x 14.0 mm. The weight of the eggs varied between 2.0 and 5.0 g (3.3±0.65 g). The mean incubation period of the Small Bee-eater was 14.4±1.01 days and both sexes took part in the incubation. The Small Bee-eater laid 56 eggs, of which 43 hatched (76.7%) and 36 flewout of the nest, making the fledgingsuccess 83.7%. The newly hatched nestlings were 3.16 g in weight and reached a maximum of 23.16 g on day 24. A reduction in weight was noticed in the last few days and 20.75g was reached on day 27. The other body parts attained maximum maturity from hatching to fledging.