A utility vehicle occupant side retention system includes a net assembly having a lower edge sliding along a guiderail secured to the utility vehicle. A rear edge of the net assembly may be attached to at least one rear attachment point on a roll over protection structure of the utility vehicle, and a front edge may be releasably attached to a front attachment point on the roll over protection structure. The guiderail may be sloped sufficiently to a vertical peak so the front edge of the net assembly may be releasably attached to the front attachment point on the rollover protection structure only if a part of the lower edge slides forwardly and upwardly to a forward end of the guiderail.