It is now well recognized that the prevalence of delayed gastric emptying in both insulin-dependent as well as noninsulin-dependent diabetes mellitus is high. Recently performed studies have shown that motor disorders of several parts of the upper gastrointestinal tract contribute to this delay in gastric emptying. Traditionally, disordered motility in diabetes mellitus has been attributed to irreversible autonomic nerve damage. However, recent observations indicate that hyperglycemia causes a reversible impairment of motility in various regions of the gastrointestinal tract. Upper gastrointestinal symptoms are highly prevalent in diabetes mellitus. These dyspeptic symptoms are not only induced by delayed gastric emptying, but altered visceroperception also plays a role in the genesis of dyspeptic symptoms. There is increasing evidence that impaired gastric emptying influences glycemia control, but the clinical consequences of these observations need further investigation. At present dyspeptic symptoms form the rationale for the treatment of delayed gastric emptying with prokinetic drugs.