BACKGROUND Adolescence is the transitional phase of growth and development between childhood and adulthood. Menstruation, which is a milestone event in a girl's reproductive life begins during this period and it is also one of the major causes of stress in this stage. Adequate knowledge and good menstrual practices can help in addressing this stress and also in preventing reproductive tract infections to a great extent. This study tries to assess the awareness with regard to menstrual practice and its determinants among adolescent girls in a rural area of Central Kerala. The study also aims to explore the social taboos related to menstrual practices. METHODS This cross-sectional study was conducted at two high schools in Thrissur district of Central Kerala. The study methodology involved visiting the selected schools and questions about menstrual practices were put to students individually ensuring adequate privacy, with the aid of a semi-structured interview schedule. 196 adolescent girls participated in the study. The data was coded and entered into MS excel. Further analysis was done using the software SPSS 16.0 version. RESULTS The percentage of girls using sanitary pad is 32.1 %, clothes were used by 12.2 % girls, and 55.6 % used either cloth or sanitary pad. Most of them disposed their sanitary pads by burning them (75.6 %), but 16.3 % threw their pads / clothes in the general waste, some flushed them in the toilet (8.1 %). 64.3 % of them washed and exposed their undergarments in the sun but 35.7 % washed and kept them inside their house. 84.7 % of girls were aware about menstruation at the time of menarche. In 58.7 % of cases the source of information was their mother. Regarding social taboos during menstruation, the most common one was inability to attend social or religious functions during menstruation (76 %) followed by restrictions in going out (9.7 %), and 7.7 % in food preparation. 7 % of girls had to sleep in a corner of the room while they were menstruating. Maternal education, family income and awareness regarding menstruation had statistically significant association with usage of sanitary pads. CONCLUSIONS Majority of the adolescent girls had awareness regarding menstruation. However, there were some who followed less than ideal practices when it comes to disposal of sanitary napkins / clothes and care of undergarments. The wrong concepts like menstruation is a ‘disease of impurity’ and menstruation occurs when ‘bad blood’ collects is still prevalent among the adolescent girls. It is of concern that the social taboos regarding menstruation are still widely embraced by the society. KEYWORDS Menstrual Practices, Menstrual Awareness, Kerala, Menstruation