Awareness and knowledge about emergency contraception (EC) has been less among Indians. Usually southern states of India have better performance of family planning than northern states. Hence Andhra Pradesh, Karnataka, Kerala and Tamil Nadu have been considered for the study. District Level Health Survey-3 (2005) was the data source. Several socio-economic demographic variables have been considered as determinants. The analysis revealed that Kerala state has highest awareness followed by Karnataka, Tamil Nadu and lastly Andhra Pradesh. Logistic regression has revealed that Muslims had less knowledge of emergency contraception while Christians had better knowledge than Hindus. Scheduled caste/tribe respondents also had less knowledge of emergency contraception. Years of schooling of respondents/spouse also emerged as important variables affecting knowledge on emergency contraception.