Abstract The main result of this paper is to show that the problem of instantiating a fifinite and path-consistent constraint network of lines in the Euclidean space is NP-complete. Indeed, we already know that reasoning with lines in the Euclidean space is NPhard. In order to prove that this problem is NPcomplete, we fifirst establish that a particular instance of this problem can be solved by a nondeterministic polynomial-time algorithm, and then we show that solving any fifinite and path-consistent constraint network of lines in the Euclidean space is at most as diffificult as solving that instance