The antibacterial, antifungal and anti-yeast activities of ethanolic extracts of 19 different Tabernaemontana species have been screened by means of the agar diffusion test, 18 species showed activity against gram-positive bacteria, 14 species against gram-negative bacteria, 5 species against, yeast and 6 species against, fungus. From most of the plants various parts have been examined, the root bark and stem bark showing the greatest activity. The antiamoebic activity of 15 species was assessed, three species showing significant activity at 0.5 mg/ml. Only two of the 14 species examined for antiviral activity showed significant activity against a single virus. 1 Part 6 in the series “Pharmacognostical studies of Tabernaemontana species”. For part 5 see reference (1)