Jonathan Tibbs (Kenneth More) is trying to sell English sporting shotguns in the wild west. He happens upon a lawless town which is the battleground between two rival gangs of cowboys. The local saloon is owned by Kate (Jayne Mansfield). Tibbs is the innocent abroad and, when mistaken for a hired gun, he is challenged to a drinking duel by a local gunslinger. In the ensuing chaos, the gunslinger is killed, and Tibbs gains a reputation as an ace 'quickdraw'. Tibbs immediately is made the sheriff by the local mayor (who has buried many predecessors in the role) and sets about bringing peace to the town. Kate falls in love with this unusual English gentleman, and they plan a life back in England - just as life gets complicated. Tibbs is accosted by local injuns whilst trying to ascertain the details of the war between the cowboy gangs. Tibbs's English charm saves the day, and he is honoured with membership of the tribe. Meanwhile both cowboy gangs have decided that Tibbs is working for the other side and determine to remove him from the town - permanently. Just as Tibbs and Kate are pinned down by the outlaws in a seemingly hopeless position, Tibbs' tribe comes to the rescue. The happy couple is married in the chapel with the tribal chief giving the bride away.
After inadvertently stopping an Indian attack on his stagecoach while traveling in the American West, an English gentleman finds himself appointed sheriff of a nearby town.