Peter and Susana Keller have had the rent on their home in Berlin, Germany, reduced by 10%.
Noise pollution experts told the court that some noise would be expected to travel but the sound of a man urinating into the toilet was "clear, distinct and plainly very irritating".
Mr. Keller said after the verdict: "I am very happy with the outcome, although it will not solve the problem in itself.
"It is though some compensation after having to put up with something which has been very unpleasant for us.
"It was not just the noise itself that was a problem but the fact that you knew exactly what the source of the noise was in complete detail.
"It was terrible to listen to if you heard it just as you were sitting down to your dinner."