An oligomerization catalyst for olefins having from 2 to 6 carbon atoms is produced by treating aluminum oxide with a nickel compound and a sulfur compound, either simultaneously or firstly with the nickel compound an then with the sulfur compound, and subsequently drying and calcining the resulting catalyst, wherein a molar ratio of sulfur to nickel in the finished catalyst of from 0.25:1 to 0.38:1 is set in this way. The catalyst and its use are also described.