This study evaluated the phytoremediation potential of Pennisetum purpureum (elephant grass) in petroleum-contaminated soils collected from Ogale, Eleme Local Government Area of Rivers State, Nigeria. The investigation focused on the reduction of Total Petroleum Hydrocarbons (TPHs) and Polycyclic Aromatic Hydrocarbons (PAHs) in the soil and the accumulation of these hydrocarbons in plant tissues after a three-month remediation period. Experimental setups included control and contaminated soil samples, with TPH and PAH concentrations monitored before and after remediation using gas chromatography. The results revealed a significant reduction in hydrocarbon concentrations in moderately contaminated soils. In Sample B, TPH and PAH removal efficiencies reached 33.19% and 78.07%, respectively, while Sample C, which was more heavily polluted, showed lower efficiencies of 3.85% for TPHs and 58.65% for PAHs. Accumulation analysis confirmed the uptake of hydrocarbons by P. purpureum, with a total of 13,004.60 ppm of TPHs and 33.98 ppm of PAHs detected in plant tissues. The uptake-to-removal ratios further supported the plant’s role in phytoextraction, particularly for high-molecular-weight hydrocarbons. These findings underscore the effectiveness of P. purpureum as a low-cost and environmentally sustainable solution for remediating petroleum-contaminated soils, especially in moderately polluted environments. The study reinforces the relevance of plant-soil-microbe interactions and site-specific conditions in enhancing phytoremediation efficiency.