This study examines the causes, treatment, and outcomes of infertility in a population of 708 couples from a single health district in England. The annual incidence of infertility is estimated at 1-2 couples per 1000 residents, with 41% of women having had at least one pregnancy. The most common causes of infertility include failure of ovulation (21%), tubal damage (14%), endometriosis (6%), cervical mucus defects or dysfunction (3%), and coital failure (up to 6%). Sperm defects or dysfunction are the most common defined cause (24%), leading to a poor chance of pregnancy without donor insemination. Infertility was unexplained in 28% of cases, and the duration of infertility significantly influenced the chance of pregnancy. In vitro fertilization (IVF) could benefit 80% of cases with tubal damage and 25% of unexplained infertility, representing up to 216 new cases per million population annually. The study highlights the need for better understanding and management of infertility, particularly in cases with prolonged unexplained infertility.This study examines the causes, treatment, and outcomes of infertility in a population of 708 couples from a single health district in England. The annual incidence of infertility is estimated at 1-2 couples per 1000 residents, with 41% of women having had at least one pregnancy. The most common causes of infertility include failure of ovulation (21%), tubal damage (14%), endometriosis (6%), cervical mucus defects or dysfunction (3%), and coital failure (up to 6%). Sperm defects or dysfunction are the most common defined cause (24%), leading to a poor chance of pregnancy without donor insemination. Infertility was unexplained in 28% of cases, and the duration of infertility significantly influenced the chance of pregnancy. In vitro fertilization (IVF) could benefit 80% of cases with tubal damage and 25% of unexplained infertility, representing up to 216 new cases per million population annually. The study highlights the need for better understanding and management of infertility, particularly in cases with prolonged unexplained infertility.