Background: Ciprofloxacin (CFX) is a second-generation fluoroquinolone that has been primarily used in the treatment of acute bacterial sinusitis. Objective: The aim of this study was to prepare and confirm electrolyte nanocomplex using ciprofloxacin and chondroitin sulfate (CS) for the nasal delivery with optimum physicochemical properties. Materials and Methods: Nanocomplex was prepared by an ultrasonic dispersion. The preparation conditions of the nanocomplex were conducted according to the ratios of 1:0.5, 1:1, 1:3 (CFX: CS, w/w) and pH condition (pH 2.0, pH 3.0, pH 4.0, pH 5.0). The physicochemical properties of the prepared nanocomplex were evaluated using the differential scanning calorimetry (DSC), X-ray powder diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), entrapment efficiency, and drug release test. Results: The nanocomplex prepared at the ratio of CFX:CS = 1:1 (w/w) had the nano-size of 582.12 ± 77.75 nm and a high entrapment efficiency of 85.39 ± 0.23%. The results in DSC and XRD showed that the CFX in the nanocomplex was in the amorphous form. Electrostatic interaction between CFX and CS was supported in the FT-IR spectrum. The dissolution rate of the nanocomplex showed an immediate release profile of more than 85% within 15 min at pH 4.0. Conclusion: The promising nanocomplex optimized in high entrapment efficiency, small particle size, and immediate release could be considered for the nasal delivery and treatment.