In situ modified carbon paste, screen-printed and PVC electrodes were fabricated for the determination of moxifloxacin hydrochloride (MOXHC). The electrodes under study revealed linear response over wide concentration range of 1.0×10-6-1.0×10-2 mol L-1 of MOXHC at 25 o C with a monovalent cationic slope. It was found that the slope is 57.2 ± 2.6, 59.2 ± 4.6 and 57.7 ± 2.7 mV decade-1 for IPVC electrodes modified with 7.5 mg NaTPB, PMA and PTA ion pairing agents, respectively, and 58.6 ± 1.7, 60.0 ± 2.0 and 59.0 ± 3.3 mV decade-1 for ISPE modified with 22, 16 and 30 mg NaTPB, RN and PTA ion pairing agents, respectively, but 60 ± 2.3 mV decade-1 for ICPE modified with 10 mg NaTPB. Moreover, the selectivity coefficient of the electrodes was determined by applying both matched potential and separate solution methods. The modified SPE sensor shows high selectivity and sensitivity for determination of MOXHC. The response of the electrodes was found to be pH independent in the range of 2-6 for ISPEs and IPVC electrodes and 3-7 for ICPE electrode. The electrodes under study have short response time. This potentiometric method can be used for determination of MOXHC in pharmaceutical preparation and the results obtained agreed with those obtained with HPLC official method. The proposed potentiometric method was validated according to the IUPAC recommendation.