Peppers (Capsicum spp.) with pungent (chili, hot pepper) and non-pungent (sweet pepper, bell pepper, paprika, capsicum) fruits are important spice and vegetable crops worldwide, especially in many developing countries of Asia and Africa. Among the five cultivated species of the genus Capsicum, C. annuum L. var. annuum is the most widely cultivated; over the past 25 years, AVRDC – The World Vegetable Center has focused on improving this commonly grown species. Other domesticated species also have been used as resistance sources against biotic stresses in breeding programs to improve C. annuum (for example, C. chinense and C. baccatum resistant to anthracnose). The major focus of the Center’s pepper breeding activities has been to identify and use host plant resistance to many biotic stresses, including viral (Cucumber mosaic virus, Chili veinal mottle virus, Potato virus Y, Tomato mosaic virus, geminiviruses), fungal (Phytophthora wilt, anthracnose, mildews) and bacterial (bacterial wilt, bacterial spot) diseases. The Center disseminates seeds of improved lines to cooperators in developing countries (usually public and private sector breeders), who make use of the germplasm in various ways: (i) direct release of supplied breeding lines as varieties through national varietal release procedures, (ii) reselection among the supplied populations according to local trait preferences and subsequent release as new varieties, (iii) use of supplied materials (possibly after further selection) as parental lines in hybrid breeding, and (iv) use in crosses in breeding programs. Examples from these categories will be presented.