The basic principles of detection of fast neutrons with liquid-scintillator detectors are reviewed, together with a real example in the form of the neutron wall array. Two of the challenges in neutron detection, discrimination of neutrons and γ-rays and identification of cross talk between detectors due to neutron scattering, are briefly discussed, as well as possible solutions to these problems. The possibilities of using digital techniques for pulse-shape discrimination are examined. Results from a digital and analog versions of the zero crossover algorithm are presented. The digital pulse-shape discrimination is shown to give, at least, as good results as the corresponding analogue version.