This present research work was conducted to determine the phytotoxic effects on tropical native plants, Ludwigia octovalvis, in order to assess its application for phytoremediation of crude oil sludge in contaminated sand. For this purpose of study, L. octavalvis plants were planted in containers containing different proportion of spiked real crude oil sludge in sand (10%, 50%, and 100% (v/v)). Degradation of crude oil sludge by L. octovalvis was measured in terms of total petroleum hydrocarbons (TPH) and was compared with TPH degradation inside control crates without plants. The findings indicated that the average TPH removal after a prolonged 42-day exposure period was high. The degrees of TPH degradation were 67.0, 42.4 and 46.2% in sand spiked with real crude oil sludge at 10, 50 and 100% respectively, whereas the degradation was only 34.7, 29.1 and 20.5% for the unplanted containers at the same respective proportions of crude oil sludge in sand. These findings give evidence that L. octovalvis has the capability to degrade hydrocarbons in crude oil sludge.