The occurrence of dipteran fly, Chrysomya megacephala (Fabricius, 1794) is reported for the first time from Royapuram fishing harbour (Chennai), Tamil Nadu, South East India. The fully grown third instar larvae of C. megacephala were collected from decaying fishes near Royapuram fishing harbour. This site is found to be the regular breeding site for C. megacephala. Larvae were reared under laboratory condition and freshly emerged adult flies from pupae were collected and identified by morphological features and molecular tools. Molecular identification through generation of DNA barcoding using mitochondrial COI gene of C. megacephala is appended.