PURPOSE: In 2009, the European Hernia Society published the EHS Guidelines for the Treatment of Inguinal Hernia in Adult Patients. The Guidelines contain recommendations for the treatment of inguinal hernia from diagnosis till aftercare. The guidelines expired January 1, 2012. To keep them updated, a revision of the guidelines was planned including new level 1 evidence. METHODS: The original Oxford Centre for Evidence-Based Medicine ranking was used. All relevant level 1A and level 1B literature from May 2008 to June 2010 was searched (Medline and Cochrane) by the Working Group members. All chapters were attributed to the two responsible authors in the initial guidelines document. One new chapter on fixation techniques was added. The quality was assessed by the Working Group members during a 2-day meeting and the data were analysed, especially with respect to any change in the level and/or text of any of the conclusions or recommendations of the initial guidelines. In the end, all relevant references published until January 1, 2013 were included. The final text was approved by all Working Group members. RESULTS: For the following topics, the conclusions and/or recommendations have been changed: indications for treatment, treatment of inguinal hernia, day surgery, antibiotic prophylaxis, training, postoperative pain control and chronic pain. The addendum contains all current level 1 conclusions, Grade A recommendations and new Grade B recommendations based on new level 1 evidence (with the changes in bold). CONCLUSIONS: Despite the fact that the Working Group responsible for it tried to represent most kinds of surgeons treating inguinal hernias, such general guidelines inevitably must be fitted to the daily practice of every individual surgeon treating his/her patients. There is no doubt that the future of guideline implementation will strongly depend on the development of easy to use decision support algorithms tailored to the individual patient and on evaluating the effect of guideline implementation on surgical outcome. At the 35th International Congress of the EHS in Gdansk, Poland (May 12-15, 2013), it was decided that the EHS, IEHS and EAES will collaborate from now on with the final goal to publish new joint guidelines, most likely in 2015.