The hexane extract of Heliotropium marifolium yielded a mixture of triterpenoids: beta-sitosterol, stigmasterol, beta-amyrin, friedelan-3beta-ol (epifriedelenol), cycloartenone, beta-amyrin acetate, friedelin and epifriedenyl acetate. Isolated triterpenoid and reference antibiotics (gentamycin/mycostatin) were tested against selected pathogenic bacteria and fungi, e.g. Escherichia coli, Staphylococcus aureus, Aspergillus niger and Penicillium chrysogenum. The inhibition zone (IZ) and the activity index (AI) of isolated compounds were recorded and it was found that epifriedenyl acetate (IZ = 17; AI = 1.06) was the most active. The present study deals with the quantification and assessment of their growth inhibitory potency. It has been reported that cycloartenone was the major triterpenoid in both in vivo (0.54%) and in vitro (0.11%) cell cultures.