Spinel oxide nanoparticles (NPs) of MnCo2O4 (MCO) and silver-doped MCO were synthesized using the combustion method. The prepared NPs were characterized via x-ray diffraction (XRD) to determine the crystalline structures. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were applied to demonstrate the morphology, shape, and size of the achieved NPs. In addition, the effect of Ag (10%) as conductor and sodium dodecyl sulfate (SDS) as surfactant on the prepared materials was investigated. The XRD results show that Ag doping of MnCo2O4 does not change the crystal structure. According to the SEM studies, the addition of SDS prevented NP agglomeration according. The synthesized nanomaterials could be used for supercapacitor application with superior performances. Among the all prepared nanomaterials, the Ag-doped MnCo2O4 NPs prepared in the presence of SDS exhibited the best pseudo-capacitive performance possessing the highest specific capacitances of 942 F g−1 at 1 A g−1 and 590 F g−1 at 20 A g−1 with excellent cycling stability (93.7% retention rate after 1000 cycles).