Background: Pregnancy is a normal physiological process in a woman's life and is accompanied by numerous of minor discomforts caused by anatomical, physiological and hormonal changes .These minor discomfort may affect the woman's quality of life and limit daily activities. The Aim of study: was to assess pregnant women's knowledge and practice regarding minor discomfort during third trimester. Research design: A descriptive study design was utilized for achievement the aim of the research. Setting: The study was conducted at antenatal clinic Ain Shams University of maternity hospital. Sample: A purposive sample was used in the current study included (353) of pregnant women's during third trimester .Tools of data collection: Two tools of data collection were used: Tool I; structured interviewing questionnaire sheet and Tool II; Self- care reported practice assessment tool. Results: The current study findings revealed that 51% of the studied sample had average level of total knowledge score regarding minor discomfort during third trimester, 26.9% of them had unsatisfactory, while 22.1% of them had satisfactory. Also, 72.2% of the studied sample had unsatisfactory level of total practice score regarding minor discomfort during third trimester, while 27.8%of them had satisfactory. In addition to that there was highly significant correlation between total knowledge score and total reported practice score of the studied sample. Conclusion: Based on the results, the current study concluded that more than half of the studied sample had average level of total knowledge score , more than one quarter of them had unsatisfactory knowledge. And less than three quarters of study sample had unsatisfactory level of total practice score regarding minor discomfort during third trimester. Recommendations: the current study recommended that design and implement periodically awareness-raising Health education programmed about minor discomfort during pregnancy using booklet, guideline, video and brochures.