This study focuses on the constructions of humanitarian practice negotiated by agencies and their workers that serve to sustain engagement in the face personal challenges and critique of the humanitarian enterprise. It employed public narrative of 129 website postings by humanitarian workers deployed with the health-focused international humanitarian organization Médecins Sans Frontières (MSF) to identify recurrent themes in personal, organizationally-condoned, public discourse regarding humanitarian practice. The text of postings was analysed with respect to emergent themes on an iterative basis. Comprehensive coding of material was achieved through a thematic structure that reflected the core domains of project details, the working environment, characteristics of beneficiaries and recurrent motivational sub-texts. Features of the co-construction of narratives include language serving to neutralize complex political contexts; the specification of barriers as substantive, but surmountable; the dominance of the construct of national-international in understanding the operation of teams; intense personal identification with organization values; and the use of resilience as a framing of beneficiary adaptation and perseverance in conditions that – from an external perspective – warrant despair and withdrawal. Moreover, recurrent motivational sub-texts include ‘making a difference’ and contrasts with ‘past professional constraints’ and ‘ordinary life back home.’ Not only does the prominence of these sub-texts highlight key personal agendas, but despite policy initiatives on stronger contextual rooting and professionalism, it also suggests continuing organizational emphasis on externality and volunteerism. Overall, postings illustrate a complex co-construction of medical humanitarianism that reflects a negotiated script of personal and organizational understandings adapted to evolving demands of humanitarian engagement.