<p>PET fibers are widely acclaimed as the most extensively produced synthetic fibers. They are distinguished by low cost, recyclability as well as excellent physical, chemical and mechanical properties. They are used in several applications such as apparel and home furnishings. Pyrazole-based disperse diazo dyes were synthesized using 3-(2-(4-(Phenyldiazenyl)phenyl)hydrazono)pentane-2,4-dione <b>(1)</b> as a starting material. Green techniques (grinding and microwave) were used to prepare the new dyes (<b>2–4)</b>. The chemical structures and formulae of these dyes were characterized by spectroscopic tools such as IR, ¹ H-NMR, ¹³C-NMR, and mass spectra. The synthesized dyes were utilized for simultaneous dyeing and functionalization of PET fabric using exhaustion method. Color strength and color fastness of the dyed PET fabrics were examined toward washing, rubbing, perspiration and light. Ultraviolet protection factor (UPF) and antimicrobial activity against <i>S. aureus</i> (gram-positive bacteria), <i>E. coli</i> (gram-negative bacteria) and <i>C. albicans</i> (fungi) were investigated. It was found that the dyed fabrics showed good color fastness properties, excellent UV protection and high antimicrobial activities. These dyed and functionalized fabrics can be used in several applications such as multifunctional garments, upholstery and blankets.</p>