Spigelian hernias are rare defects of the abdominal wall. Our aim is to analyse the bibliography and present a series of 28 patients. A Medline bibliographical study was performed between 1970 and 2000 with analysis of the number of cases, series, ratio of cases to year and type of journal. We also present a personal study and analyse epidemiological, diagnostic, and treatment factors. There are 159 articles, 479 cases, and 19 series of more than five patients published in 85 journals (42.3% medical). Our diagnosis was preoperative in 75%, and programmed surgery was 3.6 times more common than emergency surgery. We found a significant relationship between hospital stay and type of surgery (P < 0.02) and surgical technique used (P < 0.001). We found that spigelian hernias have a multidisciplinary interest; they are given almost equal treatment in medical and surgical journals; preoperative diagnosis can be established in 75% of cases; and the best results are offered by the extraperitoneal laparoscopic approach.