Nickel composites reinforced with multiwalled carbon nanotubes (MWCNT) are manufactured via hot pressing. The precursor blends are processed by a colloidal mixing method, which mixes the Ni with a dispersion of MWCNT in ultrasound. The structure of the MWCNTs is evaluated with Raman spectroscopy in order to assess the defect situation, observing that despite increasing the amount of defects, the nanotubes retain their structure. After sintering, interfacial interactions between the MWCNTs and Ni are studied by different approaches. The sintering is analyzed in situ by high temperature X-ray diffraction, noticing no phase formation (particularly, Ni3C) throughout the process. Moreover, the MWCNT/Ni interface is studied with transmission electron microscopy. The observed interface is well defined, conserving the Ni its crystallographic structure. This study shows that no interfacial products are generated by this manufacturing method, thus proposing it as a suitable candidate when the retention of the nanotube original features is needed.