As a novel experience, aluminum-matrix composites reinforced with 0.4 wt. % multi-walled carbon nanotubes (MWCNTs) were successfully fabricated using the accumulative roll bonding (ARB) process. In order to fabricate Al-MWCNT composites by ARB processes, it was essential to investigate the effect of various parameters on the bond strength of aluminum strips. The effects of MWCNTs dispersion, thickness reduction, quantity of MWCNTs at the interface, and rolling temperature on the bond strength of the commercial pure aluminum sheets in the peeling test were studied and Optical microscopy (OM) and scanning electron microscopy (SEM) were also used to evaluate the surface conditions of the peeled surfaces. Then Al-MWCNT composites in the three quantities of MWCNTs (0.1, 0.4 and 0.7 wt.% ) were fabricated. In order to achieve optimum MWCNT concentration, mechanical properties and the microstructure of composites in different MWCNT concentrations were compared with each other. For the ARB technique, the optimum CNT content achieved in the composite structure was 0.4 wt.%. The microstructure and the fracture surface of the composites were studied during various ARB cycles by scanning electron microscopy (SEM) and optical microscopy (OM). Their mechanical properties were also measured by tensile and Vickers hardness tests. The dislocation density and grain size changes during deformation were calculated using a recently developed JAVA based software, Materials Analysis Using Diffraction (MAUD), which was based on Rietveld’s whole X-ray pattern ?tting methodology. The results indicated that compared to the spread method, using the solution dispersion (SD) method to disperse MWCNTs reduced aluminum strips' bond strength. Therefore, spread dispersion method was used for investigating the effects of other parameters on the bond strength of aluminum strips. It was found that after 8 cycles of ARB process, Al-0.1 wt.% MWCNTs composites had non uniform dispersion . On the other hand, composites with 0.4 and 0.7 wt.% MWCNTs showed a better distribution after 8cycle. Also, the investigation of 8 cycle ARBed composites in three wt.% of reinforcement indicated that Al-0.4 wt.% had higher tensile strength in comparison with other composites. So, it can be deduced from this study that Al-0.4 wt.% MWCNTs composites are the optimum composites. The Al-0.4 wt.% MWCNT composite microstructures showed excellent MWCNTs distribution in the aluminum matrix on a micrometer scale after 12 ARB cycles. It can be concluded that that increasing the number of ARB cycles to 11 improved the elongation and the tensile strength of the composites. However, these same properties were declined at the final 12 th cycle due to the development of micro-cracks in the composite strip. SEM fractographs of fracture surfaces revealed that the fracture mode of the composite was changed to the brittle type in the final cycles, while that of monolithic aluminum was ductile. The crystallites size, as measured by MAUD software for Al-MWCNTs composite produced by 12 cycles of ARB process, reached to 91 nm. Keywords: carbon nanotubes, aluminum matrix composites, accumulative roll bonding, microstructure investigation, mechanical properties, fracture surface