In a prospective hospital based surveillance, 1454 children clinically diagnosed as typhoid fever were enrolled during the period between 1990 to 2000. Of them 336 (23.1%) children were positive for Salmonella enterica serotype Typhi by blood culture. A declining trend of hospitalization and identification of the pathogen was observed from 1992 to 2000 as compared to 1990-1991. A declining trend of resistance to the commonly used anti-typhoid drugs was seen in the S. enterica serotype Typhi isolates. Recently in 2000, nine strains were detected as ciprofloxacin resistant. Misuse and overuse of ciprofloxacin for the treatment of typhoid fever influenced the development of ciprofloxacin resistant strains of S. enterica serotype Typhi in and around Kolkata.