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Summary Carbon nanostructures like multiwalled carbon nanotubes (MWCNTs) offer promising solutions for addressing asphaltene-related challenges in the crude oil industry. Here, MWCNTs were synthesized via the pyrolysis process, and thoroughly characterized using various analytical techniques including Raman spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, X-ray fluorescence (XRF), transmission electron microscopy, the Brunauer-Emmett-Teller technique, and thermogravimetric analysis (TGA). Subsequently, these MWCNTs were utilized to adsorb asphaltenes from both toluene solutions and actual crude oil samples. XRD, scanning electron microscopy (SEM), and elemental composition analysis were used to analyze the asphaltenes, alongside examining asphaltene adsorption isotherms and kinetics under optimal conditions obtained from response surface methodology coupled with central composite design (RSM-CCD) approach. The developed model exhibited a high accuracy level in predicting the asphaltene adsorption capacity within the specified experimental parameters with R2 = 0.9938 and an adjusted R2 = 0.9859. The maximum capacity of asphaltene adsorption of 709.82 mg/g was obtained at the initial concentration of the asphaltene solution of 1000 mg/L, a contact time of 77.45 minutes, an MWCNT dosage of 0.287 g, and a stirring speed of 517.29 rev/min at 363°K. The asphaltene adsorption kinetics and isotherms toward MWCNTs were consistent with pseudosecond-order and Freundlich models, respectively, suggesting the predominance of a heterogeneous surface multilayer mechanism. Additionally, asphaltene dispersant tests (ADTs), viscometry, and microscopy analysis indicate that synthesized MWCNTs notably delayed the asphaltene aggregation in actual petroleum at an optimal concentration of 200 ppm, achieving a dispersion effectiveness of 70.97% according to ADT experiments. This is due to the large MWCNT surface and favorable interactions between nanoparticles and asphaltene components, leading to efficient control of deposition/aggregation of asphaltene in petroleum. The obtained results suggest that MWCNTs can serve as economically viable and environmentally sustainable asphaltene inhibitors and dispersants for oilfield operations, and their use can address the limitations associated with other nanoparticle types and mitigate issues caused by asphaltene precipitation and deposition.