Insulinomas are rare tumors, with an approximated annual incidence of 1–4 per 1 million [1]. They may be sporadic or a part of an inherited syndrome, most often multiple endocrine neoplasia type 1 (MEN1). Similar symptoms exhibit in the even rarer condition of noninsulinoma pancreatogenous hypoglycemia syndrome (NIPHS). The key symptoms encompass neuroglycopenic and hypoglycemic ones, and diagnosis aims to verify this biochemically, while imaging is used to localize the tumor(s). For the surgeon, diagnosis and imaging are both extremely important before embarking on surgery; otherwise, unnecessary surgery may ensue. The main problems are the sometimes nonspecific symptoms not recognized as hypoglycemia, with potential devastating consequences, including permanent hypoglycemic brain damage; the sometimes difficult localization procedures; and the potential of malignancy, multiple tumors in MEN1, and, rarely, diffuse hyperplasia resembling nesidioblastosis.