From 1853 the profession of "Médecin de Colonisation" (Doctor of Colonization) was organized in Algeria to serve the so-called "territories of colonization". These doctors, the majority of them French, many former medical officers of the Army, were placed in charge of vast medical districts. At the beginning of the twentieth century with the birth of the "Assistance médicale indigène" ("native" medical care) these doctors were assisted by "auxiliaires médicaux indigènes" ("native" medical auxiliaries"). The First World War and the exigencies of the post-war era gave rise to new sanitary formations, such as the “Assistance aux mères et aux nourrissons” (Assistance for mothers and infants), which introduced into the colonial medical landscape of Algeria a new actor: the “Infirmière-visiteuse coloniale” (colonial district nurse). The relationships between these agents of colonial health were complicated, conflicted and entangled, as doctors of colonization attempted to reimpose their influence over their subordinates, native medical auxiliaries, who had been the privileged interlocutors of rural populations during the war. How were these conflicts translated in the organization of the profession of Doctor of Colonization? How did they play out on the ground, in the daily work of these men and women? The colonial archives are rich in many episodes of conflict and reorganization. This paper draws on these episodes to highlight the difficulties of trying to manage a colonized society in a state of constant change, in which the place of "natives", but also women, in the colonial order was in question.