AbstractGuaiacol (2‐methoxyphenol) and its 5 derivatives such as 4‐allyl‐2‐methoxyphenol,2‐methoxy‐4‐propenylphenol, 2‐methoxy‐4‐propylphenol, 4‐hydroxy‐3‐methoxybenzylamine and 4‐chloro‐2‐methoxyphenol were oxidatively polymerized on platinum electrodes in 0.1 M NaOH solution. The polymer modified electrodes were then checked for their responses towards biologically important analytes such as hydrogen peroxide, ascorbic and uric acids, dopamine and acetaminophen under flow injection conditions. The effect of a monomer chosen on the permselective properties of the deposited film is thoroughly discussed. Feasibility of the application of these polymer modified electrodes in selective flow injection detection of hydrogen peroxide and dopamine is demonstrated.