This study presents the preparation method and characterisation of activated carbon (AC) from pomegranate waste by using chemical with microwave activation. Pomegranate peels in powder form were impregnated in 40–60 %wt sulphuric acid with different ratios (1:3 of pomegranate to sulphuric acid) and times (2–6 h) for chemical activation. The impregnated samples were activated in microwave under inert atmosphere at different powers (450–900 W) and activation times (7–21 min) to produce AC. Design-Expert software (version 13) was selected with the I-optimal method to analyse the effects of AC preparation variables. The preparation variables, including acid concentration, impregnation time, impregnation ratio, microwave power and activation time, with their effects on the adsorption capacity of methylene blue dye, were investigated. On the basis of the obtained maximum methylene blue number, the AC and raw material were characterised via Brunauer–Emmett–Teller test, field emission scanning electron microscopy with energy-dispersive X-ray analysis, Fourier transform infrared spectroscopy and X-ray diffraction analysis. Results indicate that the AC produced from pomegranate peels achieves a sufficient surface area of 1431.8 m²/g and a total pore volume of 1.6236 cm³/g with a spongy and amorphous nature with minor crystal characteristics. It can be used as a low-cost product with desirable surface characteristics. These results promote the use of AC prepared from pomegranate waste as an obtainable and low-cost adsorbent.