We have studied La0.8Sr0.2MnO3 (LSMO) nanoparticle-decorated carbon nanotubes (CNTs) by means of the electron spin resonance (ESR) spectroscopy in view of our previous work on the magnetic and electrical properties of the system. One of the line components of the ESR spectrum reflected a paramagnetic-superparamagnetic phase transition at T-SP similar to 200 K, which is accompanied by a concomitant metal-insulator transition (MIT) associated with charge transport taking place through the CNTs network triggered by the LSMO nanoparticles. On the other hand, another ESR line component revealed anomalies at T-WL similar to 170 K as well, attributable to a 2D weak localization effect of the spin/charge carriers. Thus, magnetic interactions and dynamics of the distinct spin species were sensitively reflected in the LSMO-CNTs system. (C) 2014 Elsevier Ltd. All rights reserved.