Background: The mother should start breast-feeding as soon as possible after the birth, to give the baby time to learn to breastfeed before the breasts become full and firm. Any problems of breast, if left untreated it may cause further complications like recurrence of the problems of breast and even breast cancer. In the Grampian study 33% of all women experienced breast problems in the first 2 weeks and 28% in the thereafter. If mothers have knowledge regarding management of breast feeding problems, they can prevent those complications. Aim of the study: Evaluate the effectiveness of teaching program on knowledge regarding breast feeding problems among postnatal mothers. Research Design:  Quasi- experimental research design (One group pre-test, posttest) was utilized in the current study. Subject:  Non probability convenient sampling technique was utilized.  The study sample includes 350 postnatal women in rural area in Minia city. Setting: This study was conducted  in five primary health care units in Minia city in  the following villages (bani –ahmed, maquosa, tua, demshir, elborgaia ).this villages was selected randomly . Tools of data collection:include : 1-Structured self-administrative questionnaire to collect data related to socio demographic data and characteristics of breast feeding, 2-Knowledge assessment tool (pre –posttest education).Result: the study revealed Significant improvement was observed in the level of knowledge post program as compared to preprogram (p < 0.000).Majority (97.4%)  of mothers had good knowledge and only 2.6% had have average knowledge post program . It found that level of knowledge posttest were significantly higher after teaching program as compared to their values at pretest. There was statistically significant difference between pretest knowledge with women education, occupation and income conclusion: Teaching program is effective in improving the knowledge of postpartum mothers. Recommendation: It's recommended that Providing the postnatal mothers   health education program about proper   breastfeeding technique   in their discharge teaching plan and maintain continuous contact with them.