Electrospinning of an aqueous poly(vinyl alcohol) and glycine solution has been used to produce nanofibers with an embedded crystalline glycine exclusively in the form of the β polymorph. The β-glycine nanocrystals are highly oriented within the polymer fibers and present good polar properties. Piezoelectric and nonlinear optical responses have been quantitatively examined showing piezoelectric coefficient deff = 12.5 pm/V and an effective nonlinear optical susceptibility two times greater than that of potassium dihydrogen phosphate (KDP). Additionally, although bulk β-glycine is metastable at room temperature, when confined inside the polymeric nanofibers, it is shown to be remarkably stable.