The plasma, fourth state of matter, is a complex, reactive and nonequilibrium environment that provides excellent avenues for nanoscale magnetic material synthesis and processing at lower reactor zone temperature in relatively shorter time duration with better control on size distribution and material properties. The plasmas used for nanomaterial synthesis exist over enormous range of densities and temperature leading to the possibility of exotic range and combinations of novel nanomaterial synthesis with desired properties. In this chapter, we present the nanophase magnetic material synthesis using three different types of plasmas from (i) pulsed laser ablation deposition (PLAD) facility with high plasma density (∼1015–16 cm−3) but relatively low plasma temperature (∼few electron volts) at substrate surface, (ii) high energy density dense plasma focus (DPF) device with high plasma density (∼1016–18 cm−3) and high plasma temperature (∼several tens to hundreds of electron volts), and (iii) atmospheric microplasma (AMP) device with relatively cold plasma with plasma density either lower or almost similar to that of PLAD plasmas. In Section 4.1, basic concepts of plasma nanotechnology and plasma classifications are generally introduced. Then the basic knowledge, challenges and objects for nanophase magnetic material in data storage and biomedical applications are briefly given in Section 4.2. With the supporting knowledge in the above two sections, synthesis mechanisms and magnetic properties of various nanophase magnetic materials by PLAD family, DPF device, and AMP device are discussed in Sections 4.3, 4.4, and 4.5, respectively. The chapter highlights the novelty of plasma as tool for nanophase magnetic material synthesis.