Cotton (Gossypium spp.) is the most important textile crop worldwide due to its cellulosic mature fibers, which are single-celled hairs initiated from the cotton ovule epidermis at anthesis. Research to improve cotton fiber yield and quality in recent years has been largely focused on identifying genes regulating fiber cell initiation, elongation and cellulose synthesis. However, manipulating some of those candidate genes has yielded no effect or only a marginally positive effect on fiber yield or quality. On the other hand, evolutionary comparison and transgenic studies have clearly shown that cotton fiber growth is intimately controlled by seed development. Therefore, I propose that enhancing seed development could be a more effective and achievable strategy to increase fiber yield and quality.