In this study, we investigate polylactic acid (PLA) crystallization under in situ biaxial extension in a nonsolvent-induced phase separation foaming process. Our ternary system consists of PLA, dichloromethane (DCM) as solvent and hexane as nonsolvent. For the first time, the formation of a shishkebab crystalline morphology is observed in such a solutionbased foaming process in certain solid-liquid phase separated systems. The formation of shish-kebabs is described based on the coil-stretch transition concept. The rapid biaxial deformation caused by macropore growth uniaxially stretches the long chains that are tied with at least two single crystals which eventually leads to the formation of shish structures throughout the polymer-rich phase. The kebab lamellae then form perpendicularly on the shish cores. The scanning electron microscopy (SEM) observations and our interpretation of the crystallization phenomena are confirmed by differential scanning calorimetry (DSC) analysis. The observation of various crystalline morphologies, particularly shish-kebabs, and the elucidation of their formation mechanisms contribute to the understanding of phase separation and pore growth as well as crystallization in such polymer-solvent-nonsolvent systems. (C) 2017 Wiley Periodicals, Inc.