Bariatric surgery induces significant and sustained weight loss and subsequently reduces obesity-related comorbidities. However, only a small percentage of patients with severe obesity undergo bariatric surgery in Denmark. There is limited knowledge about the experiences with and possible reservations to bariatric surgery among secondary healthcare providers. The aim of this cross-sectional study was to investigate referral patterns and knowledge regarding the criteria for bariatric surgery among Danish secondary healthcare providers, treating obesity-related diseases. A questionnaire regarding experiences with and reservations to referring patients for consideration for bariatric surgery, along with thoughts to specific patient cases were sent to several specialists: endocrinologists, obstetricians and gynaecologists, orthopaedic surgeons and otorhinolaryngologists. Most questions required responses on a 5-point Likert scale and frequency distributions were calculated. A total of 345 (44%) specialists responded to the questionnaires. Good knowledge of the criteria for referral to bariatric surgery varied among the specialist from 6% to 68%. One of the main issues was a concern about the medical and surgical postoperative complications, which was a barrier to and influenced referral decisions. Furthermore, specialists were more likely to refer patients to bariatric surgery when patients requested this. Except for endocrinologists, the Danish secondary healthcare specialists interviewed have limited knowledge about bariatric surgery, which results in a reluctance in referring patients. Our results indicate that there is a need to improve knowledge among specialists, regarding the indications, criteria and outcomes for bariatric surgery to establish a more pro-active, specialist led approach to referrals.