<p>The trans-border human trafficking crime has consistently defied law enforcement in Nigeria. Past enactment of the ‘Trafficking in Persons Law Enforcement and Administration Act’ and the subsequent creation of the ‘National Agency for the Prohibition of Trafficking in Persons’ by the Nigerian government merely impacted internal human trafficking while much of the cross-border aspect suffered neglect. Arguably, this appears largely exacerbated by the Economic Community of West African States’ Free Movement of Persons’ protocol that obfuscated much illegal cross-border trafficking and hindered efficient monitoring. The paper investigated how the government’s efforts to adequately enforce the Trafficking in Persons law in Nigeria has been derailed by the abuse of ECOWAS Free Movement of Persons protocol at the borders. Relying on the transnationalism approach, the study argues that the protocol, despite its benefits, inadvertently aided trans-border human trade. Employing the documentary method of data collection with the pretest-posttest research design, it concluded that the misuse of the said protocol was an impediment to enforcement of the cross-border human trafficking law. The paper advocated a renewed push to review the ECOWAS Free-movement protocol provisions with a view to checkmate the cross-border human trafficking scourge and enhance Nigeria’s efforts to stem the tide.</p>