Salacia reticulata Thw. (Celastraceae) is widely used in traditional systems of medicine for the natural control of diabetics. However, S. reticulate is obtained from the wild and hence its popular use creates a huge pressure on its limited supply. Therefore, in the present study we evaluated the potential of an alternative natural antidiabetic candidate, Salacia chinensis (Celastraceae), by means of morphological, physico-chemical, phytochemical and bioactivity analyses. Gross morphological characters were compared based on taxonomically important vegetative and reproductive characters of leaf and petiole of both plants. Physico-chemical and phytochemical parameters were performed according to methods described by WHO. Total phenol content (TPC) and, total flavonoid content (TFC) were determined by using Folin–Ciocaltueand aluminum chloride methods, respectively. Radical scavenging activity was investigated by means of 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) and ABTS+ radical scavenging assays. Results were analyzed by the General Linear Model (GLM) of ANOVA followed by Duncan’s Multiple Range Test (DMRT). LC50 values of brine shrimp toxicity were generated using probit analysis. The most distinguished morphological features were leaf length, width and leaf margin, which varied significantly between the two species. All tested physico-chemical parameters were within the acceptable levels. Qualitative phytochemical analysis and thin layer chromatographic profiles revealed the presence of all tested compounds and some common spots in both species, respectively. Moreover, both plants exhibited marked levels of radical scavenging activity, brine shrimp toxicity, TFC and TPC in varying levels. Results revealed that all monitored parameters displayed positive results in S. chinensis, thus partially justifying its use as an alternative natural antidiabetic source. This could promote the sustainable utilization of S. reticulata by easing its demand. Further, the generated findings could be effectively utilized for the standardization of S. reticulata and S. chinensis for upgrading the Sri Lankan pharmacopeia.