To address the growing concerns about the impact of synthetic pesticides on human and environmental health issues related to it, it is important to explore eco-friendly pest management strategies. This study evaluated the biocidal activity – mortality and fecundity – of Ocimum gratissimum and O. basilicum essential oils on Myzus persicae Sulzer and Aphis fabae Scopoli. Three concentrations used by ingestion (0.001, 0.01 and 0.1%) and by contact (0.01, 0.1 and 0.2%) for each essential oil were compared to the control (sucrose 15%). Both essential oils significantly induced aphid mortality and inhibited their fecundity compared to the control. However, higher concentrations – 0.1% by ingestion and 0.2% by contact – exhibited pronounced effects on aphid mortality. Regarding fecundity, aphid behaviour varied according to the essential oil and application method. A comprehensive chemical analysis using gas chromatography-flame ionization detection (GC-FID) coupled with gas chromatography-mass spectrometry (GC-MS) analysis indicated that the major compounds in O. gratissimum essential oil were thymol (28.3%), p-cymene (22.0%) and terpinene (10.6%), while O. basilicum essential oil contained estragol (75.2%), linalool (8.7%) and methyl eugenol (2.9%). In light of these findings, the potential use of Ocimum spp. essential oils as biopesticides for integrated pest management in vegetable crops and the harmful effects of synthetic pesticides on human health and the environment are discussed.