Mental illness raises many human right issues. People with mental disorders are exposed to a wide range of human rights violation both within and outside the health care context. People with mental illness and their families do not exercise their rights, because of lack of awareness that they have such rights, lack of knowledge about how to effectively assert their rights, and lack of confidence in asserting their rights. The most important factor in ensuring patient’s rights is the knowledge of the mental health professionals. The objective of the study to assess the knowledge regarding the rights of mentally challenged Patients among Staff Nurses. A Descriptive research Design was conducted at Rohilkhand Medical College & Hospital, Bareilly, U.P. 40 Staff Nurses were selected through purposive sampling technique and data was collected by using structured knowledge questionnaire. The study result showed that 50% Staff Nurses had Moderate knowledge, 2.5% had adequate knowledge and 49.5% had inadequate knowledge. The study concluded that there is a need of continuing education of Staff Nurses regarding the rights of mentally challenged Patients.