Abstract: Highly monodispersed and colloidal magnetite nanoparticles (MNPs) with controlled particle sizes and biocompatible polymer coatings have recently revealed a good ability for magnetic fuid hyperthermia (MFH) applications. Herein, we focused on probing the thermal abilities of polyacrylic acid (PAA)-decorated MNPs (PMNPs) under alternating magnetic feld (AMF) with diferent frequencies and feld amplitudes. The as-prepared PMNPs were fully characterized using various techniques including TEM, FTIR, DLS, TGA, and VSM. The results illustrated uniform colloidal well-dispersed ultra-small MNPs (core=5 nm) with hydrodynamic sizes of (DH =60 nm) and superparamagnetic behaviour. PAA-MNPs in water showed a good self-heating efciencies, particularly when minimal concentration of MNPs (2.5 mg/mL) were employed. Heating profles depicted that hyperthermia temperatures (42 °C) can be reached in relatively short times and could rise up to 53 °C. Heating abilities and SAR values as functions of frequency, feld amplitude of AMF and concentration were systematically investigated. A remarkable increase of SAR with decreasing concentration and increasing frequency as well as amplitude was found. For instance, SAR was found to be 36 W/g and 6.75 for concentration of 2.5 and 10 mg/ml, respectively. Thus, it was concluded that by altering main MFH parameters, the heat can be efectively tuned for possible use in magnetic hyperthermia.