Electrospinning has emerged as an attractive technique for the fabrication of ultrafine fibers in micro-/nano-scale fineness. However, it is still a huge technological challenge in achieving aligned fibers and arrays due to the inherent chaotic motion of an electrospinning jet. We report herein a novel spinning approach termed stable jet electrospinning to offer a facile solution to the noted issue. It involves judiciously using an ultrahigh molecular weight poly(ethylene oxide) to formulate the viscoelasticity of a spinning dope such that a very long and stable jet can be formed during electrospinning. This consequently allows for readily collecting and fabricating individual fibers, multi-filament yarns, well-aligned unidirectional fiber arrays in a large area, and ordered fiber patterns by controlling fiber placement. Our approach could thus open up the possibility of achieving continuous aligned ultrafine fibers and structures in a straightforward and scalable fashion, suitable for a variety of practical applications.