The application of ruthenium dioxide (RuO2) modified electrodes to the electrocatalytic detection of the saccharide-related antibiotics streptomycin, novobiocin and neomycin, at low fixed potentials, was investigated. The RuO2-modified graphite-epoxy composite electrodes give extremely stable and reproducible catalytic oxidation currents for these antibiotics at potentials as low as +0.2 V (versus Ag-AgCl). Rapid quantification at the micromolar level is therefore possible. Standard calibration graphs for streptomycin and neomycin yielded slopes of 4.43 and 0.08 nA µM –1 over the linear ranges of 1.5 × 10–6–2.5 × 10–4 and 1 × 10–5–2 × 10–3 M, respectively. Owing to its catalytic oxidation by the RuIII-RuIV couple, rather than the RuIV-RuVI transition (which catalyses the oxidation of streptomycin and neomycin), novobiocin could be detected at a lower (+0.2 V) potential, with a sensitivity of 1.31 nA µM –1. Detection limits of 1.5, 6.0 and 10 µM were obtained for streptomycin, novobiocin and neomycin, respectively. These catalytic surfaces can be renewed (by polishing), with a surface-to-surface reproducibility of 6.5% for the detection of 5 × 10–5 M streptomycin. The analytical application of RuO2-modified carbon paste electrodes to the analysis of these antibiotics by flow injection was investigated, with a view to liquid chromatographic separation with electrochemical detection applications.