The law relating to jury trials is diverse in its sources and by no means consistent in its content. This article examines aspects of the law relating to jury trials and the extent to which the verdict of a jury in a criminal trial may be challenged on appeal because of defects in the way the trial was conducted or the manner of taking its verdict. The relevant law may conveniently be examined in a sequence corresponding to the course of the trial: the selection of the jury; the hearing of the case; the jury's consideration of the issue of guilt or innocence, and the rendering of its verdict.