In this work, the carbon paste electrode (CPE) was modified using the cis-dioxo-bis[3-methoxy-2,2-dimethylpropanediamine] molybdenum(VI) complex and 1-octanaminium,N,N,N-trioctyl bromide. Using the modified electrode, the best separation of anodic peaks for ascorbic acid and dopamine was obtained in solutions with pH 5.0 and the linear range for ascorbic acid is acquired in the range from 3.0 × 10-6 to 6.0 × 10-3 M and for dopamine from 2.0 × 10-6 to 1.0 × 10-2 M. The limits of detection (S/N = 3) were 4 × 10-7 M and 5 × 10-7 M for dopamine and ascorbic acid, respectively. Surface regeneration and the very easy preparation of the modified CPE together with the very good peak resolution and sub-micromolar detection limits designate the prepared carbon paste electrode appropriate for simultaneous voltammetric determination of dopamine and ascorbic acid.