The current work boons the characterization and synthesis of bare and CNT decorated MgO green nanoparticles using the peel waste of dragon fruit as a promising material for antibacterial activity. MgO and MgO/CNT were synthesised by green method. The particle sizes were calculated as 31 and 36.17 nm for MgO and MgO/CNT. SEM and EDX were used to evaluate the microcapsules’ morphological characteristics and elemental makeup, respectively. From the optical study it was observed the band gap values for MgO and MgO/CNT was found to be 4.76 and 3.87 eV. When CNT was added to MgO (MgO/CNT) the absorbance peak and band gap decreases. From SEM analysis, revealing of well-defined and uniformly distributed nanoparticles with spherical like structure for MgO. The tubular formation confirms the presence of CNT in MgO. The interaction between CNTs and MgO, as well as the presence of organic compounds are observed from FTIR studies. Assessment of MgO and CNT decorated MgO nanoparticles’ antibacterial efficacy against S. aureus and E.coli using a biosafety technique. Potent antibacterial activity against bacteria of both gram-(+ve) positive and gram-(-ve) negative is demonstrated by CNT-doped MgO NPs, as well as it has a higher level of inhibition than MgO.