Background: Asthma is a complex chronic inflammatory disorder, with many factors influencing its prevalence. Diet’s impact on the symptoms of the disease is still controversial, although various dietary patterns or specific nutrients have been studied. Objective: The objective of this crossover, randomised, two-period study was to examine the potential of controlling dietary histamine intake and, through this, alter asthma symptoms in children with mild intermittent asthma. Methods: Children with mild intermittent asthma were randomly assigned to either a high- (HH) or low- histamine (LH) diet, based on the Mediterranean pattern, for 4 weeks (t0). This was followed by a 2-week washout period (t1) before patients crossed to the alternative diet (t2) for an additional 4 weeks. Children were assessed at baseline and after the completion of each diet phase. They also recorded symptoms and peak flow throughout the intervention. Adherence to the dietary intervention was assessed via four random 24-hour recalls for each intervention period and comparison of selected qualitative and quantitative indices, i.e. histidine, food choices, energy, macro- and micronutrients intake. Results: Eighteen children (10 boys), with mean age 11,5±3,1years were recruited and completed the study. A trend for prolonged and more severe symptoms was observed during HH. There was good adherence to the diet during remission periods, but lower compliance during symptomatic periods, particularly for the HH group. The mean actual intake differed significantly between the two diets, not only in the histamine content but also in energy, sugar and various micronutrients, including sodium. Conclusions & Clinical Relevance: Diet may have an active and direct impact on asthma symptoms. A diet deviating from the Mediterranean standard in terms of high energy, histamine, and salt has been associated with asthma worsening. Dietary interventions in asthmatic patients should be prospectively evaluated for a longer period and with proper nutritional education.