Micron-sized fibers of UHMWPE reinforced with CNT were fabricated by the electrospinning process. Conditions for a metastable mutual solution of UHMWPE and CNTs were found at elevated temperature. These solutions were used for electrospining using a device having controlled temperature and gaseous environment around the electrospun liquid jet. The fabricated micron-sized fibers exhibited the reinforcing CNTs as self-organized nano-ropes embedded within them. A post-spinning drawing process enhanced the mechanical properties of the composite fibers to the level of 6.6 GPa strength and elongation at break of 6%. The CNT nano-ropes form spontaneously in the liquid jet during electrospinning, and provide the reinforcement framework which is amenable for post-drawing of the fibers for subsequent utilization as composite nanofibers. The experimental results exhibit the highest strength value reported to date for electrospun fibers.