A novel process for preparing stable granulate which comprises amoxicillin trihydrate and a sugar, and to novel stable granulate comprising amoxicillin trihydrate and the sugar as well, for reconstitution with water into fine stable homogeneous aqueous suspension is described. The novel process omits preliminary process step for preparing fine particle size of micronized amoxicillin trihydrate used subsequently in the granulation process known in the art, for example grinding or micronizing of said antibiotic. In a preferred aspect of the invention the novel stable granulate comprises amoxicillin trihydrate and the sugar, preferably sucrose, free of any pharmaceutically acceptable excipient. Novel granulate, which is easily dissolved in water to form smooth aqueous suspension immediately, is used for treating bacterial infections in humans or animals, especially in pediatric patients and in the geriatrics.