The UPR (unfolded protein response) or ER (endoplasmic reticulum) stress response was first described 20 years ago. The field of ER stress has expanded tremendously since, moving from basic biology in yeast to human neurodegenerative, inflammatory, cardiovascular and neoplastic diseases. The ER stress response has also been implicated in diabetes development, affecting both insulin production by pancreatic beta-cells and insulin sensitivity in peripheral tissues. In the present mini-review, we focus on recent progress in the field of ER stress in pancreatic beta-cells. Recent advances in the understanding of lipotoxic ER stress and beta-cell recovery from ER stress are discussed.