The business environment in Nigeria is characterised by a complex interplay of long-standing structural issues and new, dynamic pressures. While existing literature often examines these challenges in isolation, there is a lack of comprehensive, longitudinal diagnostic surveys that capture their evolving nature and relative severity from the perspective of enterprise operators. This study aims to systematically diagnose and rank the persistent and emerging challenges faced by businesses operating within the country. It seeks to identify shifts in the constraint hierarchy over time and analyse sector-specific variations. A large-scale, stratified survey of 1,850 registered small, medium, and large enterprises was conducted across six geopolitical zones and multiple sectors. Data were collected via structured questionnaires, with analysis employing descriptive statistics, factor analysis, and rank-order scaling to determine the prevalence and perceived severity of identified challenges. Infrastructure deficits, particularly erratic power supply and poor transport networks, were persistently ranked as the most severe constraint by over 80% of respondents. However, a significant emerging challenge is digital security, with 65% of firms reporting cyber-fraud incidents as a major operational threat. The hierarchy of constraints shows notable variation between manufacturing and service-sector firms. The business landscape continues to be dominated by entrenched infrastructural problems, but the rapid digitisation of the economy has introduced a new layer of critical, technology-related risks that compound traditional operational difficulties. Policy interventions must adopt a dual-track approach: accelerating foundational infrastructure development while concurrently establishing robust legal and technical frameworks for cybersecurity and digital commerce. Sector-specific support programmes are required, rather than blanket policies. business environment, diagnostic survey, operational constraints, infrastructure, cybersecurity, Nigeria This paper provides a novel, ranked diagnostic dataset that quantifies the shifting hierarchy of business constraints, offering evidence for targeted policy formulation.