Breast cancer is the leading cause of cancer-related deaths among women globally including Tanzania. However, timely access to diagnosis remains a challenge due to lack of specialized facilities. Most patients presents with advanced stages of the disease making management impossible. This leads to an increase in breast cancer-related mortality. Little is known about knowledge and practices on breast cancer screening in Tanzania. This study described knowledge and practices on breast-cancer detection and associated challenges among women aged 35 years and above in Morogoro rural District in Tanzania. This descriptive cross-sectional study was conducted in Lubungo, Newland and Fulwe villages at Mikese ward in Morogoro rural District from June and July 2017. A standardized questionnaire was used to obtain information from 130 study participants regarding breast cancer knowledge and practices. Data were analyzed using (SPSS) software version 23 and descriptive statistics were summarized in frequencies and percentages. One hundred and thirty women were studied, all participants have heard of breast cancer; 71.5% knew the effects of breast cancer; 37.7% knew about the signs and symptoms. The most frequently reported cause and risk factor of breast cancer were putting money under brassiere (30.8%) and fat diet (17.7%) respectively. The participants (73.8%) have never heard of breast self-examination (BSE) as an early detection method of breast cancer hence do not practice it. Lack of knowledge on early signs and symptoms of breast cancer was reported as the main challenge for breast cancer screening (73.8%). The frequently reported source of information about this disease was television/radio programs (83.1%). Most of the women have heard of breast cancer but they lack adequate knowledge on its risk factors, causes, symptoms and effects. The majority of the women do not practice BSE due to lack of knowledge. Efforts to improve women's knowledge on breast cancer is warranted.