Cataract surgery is the most common surgery in the world, with an estimated 25 to 30 million procedures performed globally each year. That works out to more than 70,000 cataract surgeries every single day. Cesarean sections follow closely behind, accounting for roughly 1 in 5 of all childbirths worldwide. Beyond those two, joint replacements, appendectomies, and hernia repairs round out the list of procedures surgeons perform most often.
Why Cataract Surgery Tops the List
Cataracts develop when the natural lens inside the eye gradually clouds over, blurring vision. It happens to most people eventually if they live long enough. By age 80, more than half of all adults either have a cataract or have already had one removed. That near-universal prevalence, combined with the fact that the surgery is quick, safe, and done on an outpatient basis, makes it the single highest-volume operation on the planet.
The procedure itself typically takes under 30 minutes. A surgeon removes the clouded lens through a tiny incision and replaces it with a clear artificial one. Most people notice sharper vision within days, and serious complications are rare. Because the surgery is so routine and recovery is so fast, it’s accessible in most countries, which drives the enormous global volume.
Cesarean Sections Are Rising Fast
C-sections are the most common major surgery worldwide. According to the World Health Organization, cesarean deliveries now account for 21% of all childbirths globally, up from about 7% in 1990. That rate is projected to reach 29% by 2030, meaning nearly one in three babies born that decade could arrive by C-section.
The numbers vary dramatically by region. In Latin America and the Caribbean, the rate is already around 43%. By 2030, projections suggest Eastern Asia could reach 63% and Southern Europe 47%. Meanwhile, sub-Saharan Africa sits at just 5%, reflecting limited access to surgical care rather than lower medical need. In the least developed countries overall, about 8% of women deliver by C-section.
Several forces are pushing rates higher: older maternal age at first pregnancy, rising rates of obesity and gestational diabetes, more multiple pregnancies from fertility treatments, and in some regions, patient or physician preference for scheduled deliveries. Whether all of these C-sections are medically necessary is a matter of ongoing debate, but the trend line is clear.
Joint Replacements in the US
Hip and knee replacements are among the most common surgeries in the United States and other high-income countries. In 2018, US hospitals recorded roughly 715,000 inpatient stays related to knee replacements and about 599,000 for hip replacements. That’s a significant jump from a decade earlier, when the numbers were around 657,000 and 422,000 respectively.
The growth is driven largely by an aging population and rising rates of osteoarthritis, the wear-and-tear form of joint disease that gradually breaks down cartilage. People are also living more active lives into their 60s and 70s, making them less willing to accept chronic joint pain. Advances in implant materials and surgical technique have improved outcomes enough that younger patients, some in their 50s, now opt for replacement rather than managing pain for decades. These numbers are expected to keep climbing through at least 2040.
Most Common Surgeries in Children
The surgical landscape looks very different for kids. The most common pediatric operation is appendectomy, with nearly 18,000 performed in one large US study. Inguinal hernia repair came second at about 12,000 cases, followed by umbilical hernia repair at roughly 7,400. A procedure to correct undescended testicles and gallbladder removal also made the top five.
Unlike adult surgeries, which are often planned weeks or months in advance, the most common pediatric procedure (appendectomy) is almost always an emergency. A child shows up with abdominal pain, imaging confirms appendicitis, and surgery happens within hours. Hernia repairs, by contrast, are typically scheduled after a pediatrician notices the issue during a routine exam.
What Counts as “Common” Depends on Scale
Rankings shift depending on whether you’re counting major operations that require general anesthesia and hospital stays or including minor outpatient procedures. Cataract surgery dominates globally because it’s minor, fast, and treats a condition that affects billions of people as they age. C-sections dominate the major surgery category because childbirth is universal and the procedure rate keeps rising.
Smaller procedures that don’t always make the headlines are performed in staggering numbers too. Skin biopsies, tooth extractions, and endoscopies each number in the tens of millions annually, but they’re rarely grouped with “surgery” in most people’s minds. When researchers and health organizations talk about the most common surgeries, they typically mean operations performed in an operating room, which is where cataract removal and cesarean delivery consistently lead the pack.