Trends in breast, cervix uteri, corpus uteri and ovarian cancers in six population based cancer registries (Mumbai, Bangalore, Chennai, Delhi, Bhopal, and Barshi) were evaluated over a period of the last two decades. For studying trends we used a model that fits this data is the logarithm of Y=ABx which represents a Linear Regression model. This approach showed a decreasing trend for cancer of the cervix and increasing trends for cancers of breast, ovary and corpus uteri throughout the entire period of observation in most of the registries. The four cancers, breast, cervix, corpus uteri and ovary, constitute more than 50% of total cancers in women. As all these cancers are increasing, to understand their etiology in depth, analytic epidemiology studies should be planned in a near future on a priority basis.