Ag nanoparticles were synthesized on the surface of a glassy carbon electrode modified with p‐tert‐butylcalix[4]arene and p‐tert‐butyl calix[6]arene by the deposition of Ag+ at an open circuit potential followed by the electrochemical reduction of the Ag+. The presence of the calixarene layer on the electrode surface controlled the particle size and prevented agglomeration. Cyclic voltammetry showed that the Ag nanoparticles on the modified glassy carbon electrode had good catalytic ability for the reduction of flutamide. The effects of calixarene concentration, potential applied for the reduction of Ag+ , number of calixarene layers, and pH value on the electrocatalytic activity of the Ag nanoparticles were investigated. The modified electrode had a linear range in differential pulse voltammetry of 10−1000 µmol/L with a detection limit of 9.33 µmol/L for flutamide at an S/N=3. The method was applied to the detection of flutamide in practical samples.