This study aimed to assess the susceptibility of different pea varieties (Grano, Kienyeji, Kigondoro, and Kiritho) to Ascochyta spp., a significant threat to pea (Pisum sativum) production. Disease severity scores and lesion radii data were analyzed using ANOVA and the least significant difference (LSD) test was used to separate the means. Ascochyta blight symptoms including purple, black, or brown spots and lesions were typical on both leaves and pods. Other symptoms observed included lower leaf blight and sunken lesions on pods. Ascochyta spp. pathogen was subsequently isolated from the diseased plant and identified based on the colony morphological characteristics. After being grown on potato dextrose agar (PDA) under an incubation temperature of 28oC, the fungal colony exhibited a typical grey colour and a woolly texture with irregularly defined edges. The study in Molo sub-county, Nakuru county, revealed significant variability in disease susceptibility among the examined pea varieties. The one-way ANOVA analysis had a p-value of 0.079, failing to reject the null hypothesis, indicating no significant difference in resistance to Ascochyta blight disease. However, Fischer's Least Significant Difference (LSD) test showcased significant differences in susceptibility among the Grano pea variety compared to the Kienyeji (p = 0.030), Kigondoro (p = 0.030), and Kiritho (p = 0.043) pea varieties. These findings are important to farmers in selecting varieties that have some level of resistance to ascochyta blight disease affecting garden pea. In the long run, this study helps in enhancing the sustainability of garden pea cultivation in Kenya. This study also adds knowledge into the existing integrated disease management (IDM) strategies for the management of ascochyta blight disease in Garden pea. This research primarily addressed disease severity and not crop yield and quality and other related factors that are also of important concern as well; hence, other researchers may consider investigating these other factors. Besides, this study helps with increasing the agricultural productivity and sustainability, in which the management of crops involves disease resistant variety selection.