Diabetes mellitus is a complex metabolic disease characterised by glucose overproduction and under-utilisation. As the incidence of diabetes expands rapidly across the globe there is an urgent need to expand the range of effective treatments. Higher plants such as Asparagus adscendens provide therapeutic opportunities and a rich source of potential antidiabetic agents. In the present study an aqueous extract of Asparagus adscendens was shown to induce a significant non-toxic 19–248% increase in glucose-dependent insulinotropic actions (P<0·001) in the clonal pancreatic β cell line, BRIN-BD11. In addition, the extract produced an 81% (P<0·0001) increase in glucose uptake in 3T3-L1 adipocytes. Asparagus adscendens also produced a 21% (P<0·001) decrease in starch digestion in vitro. The present study has revealed the presence of insulinotropic, insulin-enhancing activity and inhibitory effects on starch digestion in Asparagus adscendens. The former actions are dependent on the active principle(s) in the plant being absorbed intact. Future work assessing its use as a dietary adjunct or as a source of active components may provide new opportunities for the treatment of diabetes