A simple electrochemical method was used to directly assess the drug-release profile. The method is based on the multiple pulse amperometric measurement of the oxidation and reduction of doxorubicin released from liposome at a MWCNTs-modified glassy carbon electrode (MWCNT-GCE). The released doxorubicin was detected at +0.60 and −0.60 V by two different oxidation and reduction processes, respectively. The third potential pulse (−1.00 V) was applied for the regeneration of MWCNT-GCE. The main advantage of this method is that there is no need for any operation for the quantitative analysis during the release of the drug from nanoparticles.