ABSTRACT:- The financial performance of listed downstream oil and gas companies has increasingly come under the academic searchlight due to a lack of consensus regarding the impact of non-financial capital reporting. Consequently, this study examined the effect of natural and manufactured capital disclosures on the financial performance of listed downstream oil and gas companies in Nigeria. To achieve this objective, an ex post facto research design was employed, utilising a census of ten downstream oil and gas companies listed on the Nigerian Exchange Group as at 31st December 2024. The study utilised panel data spanning a ten year period and employed panel regression analysis via E-Views 12 statistical software to ensure analytical rigour. The empirical results revealed that Natural Capital Disclosure does not significantly influence the Return on Assets (ROA) of the sampled firms. Conversely, Manufactured Capital Disclosure was found to have a statistically significant but negative effect on financial performance, suggesting that intensive infrastructure and technological reporting may coincide with reduced short term asset efficiency. Based on these findings, the study concludes that while integrated reporting is essential for transparency, its immediate financial benefits remain elusive in the Nigerian downstream sector. The study recommends that the Financial Reporting Council of Nigeria should strengthen regulatory oversight to enforce mandatory environmental disclosure standards. Furthermore, industry associations should standardise reporting practices to align with international best practices, ensuring that capital disclosures provide more value relevant information to investors..

KEYWORDS: Natural capital disclosure, manufactured capital disclosure, Return on Assets, firm Size and Corporate Financial Performance.