Modal verbs are known to be a difficult area in both teaching and translation. In translation modals seem to pose certain problems due to their notoriety and ambiguity. This paper examines some of the problems encountered when translating modals from English into Arabic (and vice versa) with special reference to deontic modality and proceeds to shed light on the role ambiguity and decontextualization have in adding to the difficulty of translation. The deontic modals in English and Arabic are examined through examples selected for the purpose of the study in an endeavor to reveal the basic reasons behind having such difficulty when treating modals in English and Arabic translation. Therefore, some techniques to ease the difficulty deontic modals (and other types of modality) pose are suggested; and in particular when dealing with two different languages such as English and Arabic. The study concludes by emphasizing the role of backgrounds in arriving at interpretations of the meanings of modals and hence have them correctly rendered in the light of the meaning intended.