The study assessed the influence of varying cooking temperatures on the antioxidant properties of the aqueous extract of Piper guineense seeds. Different portions of the aqueous extract of P. guineense seeds were cooked at different temperatures which include 50 oC, 70 oC, and 90 oC for 10 minutes, while the remaining portion was allowed to stand for 10 minutes at room temperature of 29 oC and all were assessed for the evaluations of reducing power, radical scavenging capacities, and total phenolic contents. The results showed that there was a significant increase in the ferric reducing power at 90 oC, however, there was no significant difference between the raw and the cooked P. guineense seeds at 50 oC and 70 oC. In addition, the radical scavenging potential of the extract was highest at 70 oC, however, none of the cooked P. guineense seeds at the selected temperatures exhibited lower DPPH scavenging property. A similar trend was observed for the phenolic content of the extract with a significant reduction at 90 oC.