The paper examines the introduction of trained female nurses for the British army men in colonial India between 1888 and 1920. It discusses the genesis of the Indian Nursing Service (INS), including the background and negotiations leading up to its formation, terms of employment, duties and working conditions of the nursing sisters. The memoir of Catharine Grace Loch, who served as the first Chief Lady Superintendent of the service is used extensively to trace the early experiences and challenges of the nursing sisters. The paper primarily argues that the INS being a new service, the colonial government maintained tight control over its functioning, and extreme conservatism in spending, thus retarding the growth of professional army nursing in India. Secondly, in examining the relations between the sisters and the (male) nursing orderlies, sub-medical and medical officers, the paper argues that the inadequate delineation of the nursing sisters’ position in the military medical hierarchy was an important reason for the undermining of their expertise and status. Thirdly, the paper contends that as an all-women service, nursing constituted an important avenue of female agency within the patriarchal colonial establishment, which subjected the sisters to scrutiny both professionally and socially. The paper analyses the resultant conditions and regulations imposed on the sisters – most of them determined by gender and class notions. Finally, the paper discusses the gradual establishment and recognition of the service as an important cornerstone for the health of the army, while highlighting the shortcomings that yet persisted up until 1920.