Most of the research work on cotton has so far been confined to cotton lint which forms only 1/3rd portion of the seed cotton. Hardly any significant effort has made to raise the quality of seed and increase its oil content. Indeed, cottonseed is a tragic story of neglect in India though it forms 2/3rd portion of the seed cotton. The average oil content of cottonseed at processing plants level is found below 15% where as elsewhere in the world it is more than 20%. Potentiality is still higher at about 25%. India needs to breed cotton varieties giving higher seed yield, higher oil, protein and lysine contents, lesser level of gossypol and linter percentage, non-shattering seeds with better resistant to mycotoxin. About 95% of cottonseed available for commercial use in India is still processed by the traditional crude method, resulting recurring loss of about 3 lakh tonnes of cottonseed oil, besides other by-products like linters and hulls. Therefore, a rigorous study on value addition and marketing of cottonseed by-products with emphasis on cottonseed oil is imparted. This book is useful to the stakeholders of cottonseed industry.