Continuous monitoring of ciclosporin whole blood levels is essential to be aware of any change in drug pharmacokinetics due to interaction with additionally applied drugs, phytochemical drugs or nutritional and environmental factors. While monitoring ciclosporin levels in a 23-year old Caucasian woman diagnosed to have focal segmental glomerulosclerosis a 6-fold higher value than expected was measured. Because the kind and the dose of prescribed drugs were unchanged a drug to drug interaction could be ruled out. Additionally, phytochemical drugs, antibiotics, antimycotics or nutritional factors such as grapefruit juice as well as alcohol and tobacco were denied by the patient. She kept her protein and sodium poor diet free of citrus fruits, rare in meat and rich in vegetables unchanged before and during the course of the unexpected high ciclosporin levels. As the elevated ciclosporin levels were closely related to her cooking habits by means of a brand new steamer we advised her to refrain from preparing her vegetarian meals in this steamer. Since then ciclosporin levels were again in relation to the administered dosage without any episode of unexpected high ciclosporin values. Repeating the experiment some weeks later no episode of unexpected high ciclosporin values occurred. Unfortunately we could only identify the cause (steamer) but not the definite reason why. The report illustrates that the bioavailability of ciclosporin may not only be influenced by drug to drug interactions with prescribed or phytochemical drugs and herbal remedies but also by some yet unknown or unidentified factors or chemicals induced or altered by eating and cooking behavior or lifestyle in general. Therefore a careful assessment of the patient's anamnestic data and lifestyle combined with an unorthodox way of thinking as well as close-meshed drug monitoring is essential to obtain the desired pharmacologic effects and to avoid adverse toxic effects.