Ernesto Bertarelli

His grandfather, Pietro, joined Serono, a pharmaceutical company founded in 1906. In 1935 Pietro became the company's managing director, a position he was succeeded in by his son, Fabio Bertarelli, in 1965. Bertarelli became CEO in 1996 and, along with his sister Dona, inherited ownership in 1998 on the death of his father. Changing the company's focus from pharmaceuticals to biotechnology, revenues increased from $809 million in 1996 to $2.8 billion in 2006. The company gained fame from its discovery of a natural hormone used in the treatment of female infertility, and its treatments for multiple sclerosis and growth hormone deficiency.

Bertarelli and his family sold the company to Merck KGaA of Germany in January 2007 for US$13.3 billion, forming the new company Merck-Serono. His family split an estimated $9 billion stake at that time, which added to previous share sales when the company floated on the NY stock market in 2000, which is now invested mainly through his B-Flexion (formerly Waypoint Capital) investment vehicle. Bertarelli currently co-chairs – with his sister Dona – the Bertarelli Foundation which focuses on marine conservation and neuroscience research.

Bertarelli met Kirsty Roper, a former 1988 Miss UK and songwriter, while on holiday in Italy in 1997. The couple married in 2000, and have three children. The couple's divorce was announced in October 2021. The couple lived in Gstaad and also spent time in their house on the shores of Lake Geneva.

In December 2008, Appledore Shipbuilders launched the hull of Project55, Bertarelli's new yacht, which was completed as Vava II by Devonport Engineering Consortium Ltd at Plymouth in February 2012

The 2017 edition of the Sunday Times Rich List estimated the family's wealth at £11.5 billion, an increase of £1.72 billion since the previous year.

Bertarelli and his family established a foundation in 1999 for promoting research and development in the field of male and female infertility, assisted reproduction technologies, andrology, genetics and endocrinology; supporting training, education and international and national exchanges in these areas through grants. The Bertarelli Foundation, in Trelex, Switzerland, merged into the Foundation FABER, in Lausanne, in 2006, and since 2008 a renewed Bertarelli Foundation has regrouped the family's numerous philanthropic initiatives in the fields of charity, health, sciences, sport and culture.

Some projects recently sponsored by the Bertarelli Foundation have been the research Centre for Neuroprosthetics at the EPFL in Lausanne; the partnership with the British government to create the largest marine reserve in the world in Chagos, in the Indian Ocean; a joint research and education program in neuroscience between Harvard Medical School and EPFL; the Swiss Sailing Grants in partnership with the Swiss Sailing Federation; and the Henna Pre-School in South Africa and a partnership with the Stoke-on-Trent YMCA that was led by Kirsty Bertarelli.

Bertarelli is a member of the Harvard Medical School Board of Fellows. In 2023, Bertarelli pledged $75 million to Harvard Medical School to "advance scientific discovery and a culture of entrepreneurship".