Critical Challenges Facing SMEs in Nigeria: A Contemporary Systematic Literature Review (2021-2026).

International audience This paper presents a contemporary systematic review of the major challenges confronting SMEs in Nigeria. It updates Gumel’s (2017) foundational study by examining how these challenges have evolved over the past decade, identifying emerging threats not addressed in earlier literature, and assessing recent policy interventions. The review was conducted in accordance with PRISMA guidelines and drew on Google Scholar, Scopus, Web of Science, EconPapers, and institutional repositories to identify peer-reviewed articles, institutional reports, and government documents published between 2024 and 2026. The Lampadarios(2015) success factors framework guided the thematic synthesis, and fifty-one studies that met the inclusion criteria were appraised using a modified Mixed Methods Appraisal Tool. Access to finance remains the most consistently reported constraint, reflected in an estimated US$236 billion funding gap and only US$4.5 billion allocated to projects, despite the Bank of Industry’s substantial ₦636 billion disbursements. This review provides the first systematic synthesis of the challenges facing SMEs in Nigeria in the post-COVID-19 and post-subsidyremoval period. It identifies disruptions by non-state actors as an emerging category of challenge and highlights the growing prevalence of credit aversion, with 51% of informal businesses now avoiding loans, up from 30%, thereby reshaping the financial inclusion landscape.