A new time‐ and energy‐saving method for the determination of asymmetric dimethylarginine in human serum is presented. Here, a newly developed eluent was used in the sample cleanup of the solid‐phase extraction whose composition makes an evaporation step redundant. After derivatization, asymmetric dimethylarginine was quantified by high‐performance liquid chromatography with fluorescent detection. The conditions of the solid‐phase extraction lead to a relative recovery of asymmetric dimethylarginine of 101%. A concentration of 25 ng/mL was found as the limit of quantification and the batch was highly linear from 25 to 800 ng/mL with the correlation coefficient R2 = 0,9999. Intra‐assay coefficients of variation <2.1% and inter‐assay coefficients of variation <3.1% indicate a high precision. Since no evaporation is necessary compared to previously published methods, this newly presented method does not only save time, but also is a cost‐ and energy‐saving alternative for the routine quantification of asymmetric dimethylarginine in serum.