To assess the knowledge of postnatal mothers regarding postnatal depression and to find the relationship between the knowledge regarding postnatal depression with selected demographic variables such as age of mother, number of children, educational status of mother, educational status of husband, occupation of mother, occupation of husband, religion, type of family, family income per month and previous history of postnatal depression. To develop an information booklet regarding the prevention of postnatal depression. A descriptive Study was conducted among postnatal mothers regarding postnatal depression in hospitals of Moga (Punjab). A non probability convenient sampling technique was used to select 200 postnatal mothers of 19-35 years of age group. Demographic variables of study were such as age of mother, number of children, educational status of mother, educational status of the husband, occupation of mother, occupation of husband, religion, type of family, family income per month and previous history of postnatal depression. A self structured questionnaire containing 30 items was utilized to assess the knowledge regarding postnatal depression. The conceptual frame work of study was based upon Orem's Self Care Theory (1959). An educational booklet on postnatal depression among postnatal mothers was developed after analysis. The data were analyzed by descriptive (mean, median & mode) and inferential (ANOVA & correlation) statistics. Results of the study revealed that 28.5% of postnatal mothers were metric passed, 37.5% of their husbands were higher secondary passed, 76.5% of postnatal mothers were house maker, and 51.5% of their husbands were in their own business, 50% of postnatal mothers were Hindu and 50% were Sikh. Whereas 52.5% postnatal mothers live in a joint family, 69% of them had family incomes ≤ Rs.5000 and 100% of postnatal mothers had no previous history of postnatal depression. 53% of the postnatal mothers were in the age group of 23-26 years, 47% of postnatal mothers were having one child followed by 66% of postnatal mothers had below average knowledge and 32.5% of them had average knowledge. Only 1.5% of postnatal mothers had good knowledge regarding postnatal depression. In the present study, age of mother, number of children, educational status of mother, educational status of husband, occupation of mother, occupation of husband, religion, family income per month had significant impact on the knowledge of postnatal mothers regarding postnatal depression but type of family had no impact on the knowledge of postnatal mothers regarding postnatal depression.