This study aims to prepare polyherbal formulations and also analyze the antidiabetic potentials of the prepared polyherbal in animals. The ethanol extracts of the leaves of <em>Smallanthus sonchifolius</em>, <em>Stevia rebaudiana, Syzygium polyanthum</em>, and <em>Camellia sinensis</em> were used in this study. The extracts of the aforementioned plants were prepared in the ratio of 2:1:1:1. The formulation was tested for antidiabetic activity <em>in vitro</em> through the inhibition of alpha-glucosidase and <em>in vivo</em> using alloxan-induced diabetes in mice. The polyherbal has an inhibitory effect with the IC₅₀ value of 26.23 μg/mL compared to acarbose (control) was 17.02 μg/mL. The diabetic animals were observed to show an obvious decline in glucose level when compared with control (P&lt; 0.001) after treatment.