The incidence of breast cancer in HIV/AIDS infected women is not well documented because they could die before detection or before development of breast cancer. With the introduction of HAART, these patients live long and have all the chance to develop breast cancer. HIV positive women with breast cancer suffers a double burden of disease hence the necessity of this study. The general objective of this study was to determine knowledge, attitude and practices affecting breast cancer screening among HIV positive women attending health facilities in Imenti South Sub County. The study employed descriptive cross section study design to collect qualitative and quantitative data. A sample size of 340 respondents was used to collect data using self administered questionnaires targeting HIV positive women from 18 years and above attending health facilities in Imenti South Sub-County. Data collected was analyzed using SPSS which included Pearson's Chi-Square (X2) and the results were presented in frequency tables. The results show there is a significant relationship between, level of education, marital status, main occupation and age on the knowledge towards level breast cancer screening. Also there is a significant relationship between age, of education, and marital status on breast cancer screening practices and finally there is significant relationship between level of education, marital status, and occupation towards breast cancer screening attitudes. The results show that 49.7% of the respondents were aware of breast cancer screening with 49.7% having heard about breast cancer screening through health care facilities. Less than half (41.2 %) of those who have ever heard of breast cancer screening, can correctly define what breast cancer screening is. Twenty point five percent of the respondent could correctly identify the appropriate age to start breast cancer screening while 33.7% of the respondent could correctly identify how often should one undergo breast cancer screening. A significant negative association was found between the attitude that breast cancer cannot be cured even if early diagnosis is made against breast cancer screening uptake (61.7 % of the participant don't agree that early detected breast cancer can be successfully treated). This belief has led the participant not to engage in breast cancer screening hence the finding; fear of positive outcome makes the respondent not to participate in breast cancer screening (63 % of the respondent strongly agreed). A number of participant (11%) also felt breast cancer screening is a culturally driven secrecy. Consequently, only 34.6% of the participant has ever undergone any of breast cancer screening method. The study therefore concludes that breast cancer awareness influences the acceptance of breast cancer screening. the study recommends the following: It is recommended that the county Government of Meru in conjunction with non-governmental organization should ensure that there are training programs on breast cancer as well as other types of cancer in the comprehensive care units in order to raise the level of awareness and the importance of breast cancer screening. The Ministry of Health should come up with a breast cancer screening policy to facilitate subsidies of consultation and screening fee and introduce mobile screening units to improve uptake.