WE report results from the first stellar occultation by Titan ever observed. As predicted by Wasserman1, on 3 July 1989 the bright star 28 Sagittarii (visual magnitude, V ≈ 5.5), passed behind Saturn's giant moon ( V ≈ 8.3), which is the only body in the Solar System that, like the Earth, has a dense, nitrogen-rich atmosphere2. The event, visible from Europe, North Africa and the Middle East, allowed us to probe Titan's atmosphere in an altitude range of ∼ 250-500 km (a pressure range of ∼250-1 μbar), where until now, there has been an 'information gap' between infrared and ultraviolet Voyager observations3-5. We also detected a central flash as the centre of Titan's shadow passed at a few tens of kilometres from Paris. This central flash allows us to estimate a finite oblateness of Titan's stratosphere, which could arise from a super-rotation of Titan's atmosphere. © 1990 Nature Publishing Group.