Abstract Recent spacecraft and ground-based observations have revealed the presence of narrow rings encircling the planets Jupiter, Saturn and Uranus. The Jovian ring is known to contain at least two small, dark, satellites of diameter between 20 and 40 km in its outer edge. The structure of the Saturnian F ring has been resolved by Voyager 1 and appears to be determined by the action of two small neighbouring satellites which were also imaged by the spacecraft. All nine Uranian rings are extremely narrow and some are appreciably eccentric. The outer 6 ring has very sharp edges and its radial width increases from 20 km at pericentre to 100 km at apocentre. This marked variation in width is also characteristic of the Uranian a and |3 rings and of a narrow ring in the Saturnian system. The structure of the Uranian rj ring is complex and may be similar to that of the Saturnian F ring. The resolution of the numerous, but well defined dynamical problems posed by these narrow rings must precede any discussion of the origin of rings. Two co-orbital Saturnian satellites that appear to move in horseshoe orbits have been discovered. The stability of these orbits and the origin of these and other co-orbital satellites are discussed.