St Mary's Hospital is home to the Alexander Fleming Laboratory Museum. Fleming discovered the antibiotic penicillin at St Mary's Hospital in 1928, a breakthrough that revolutionised medicine and earned him a Nobel Prize.

Alexander Fleming with a culture plate

Visitors to our free museum can see Fleming's laboratory, restored to its 1928 condition, and explore the story of Fleming and the discovery and development of penicillin through displays and video.

Visit the museum

Our address: St Mary's Hospital, Praed Street, London W2 1NY.

Admission is free.

Opening hours

The museum is open Monday - Thursday 10:00 to 13:00 for walk up visitors. Visitors can arrange visits outside of these times on weekdays by advance appointment subject to availability.

As the museum is on a confined site, groups are kindly asked to make an advance appointment.

The museum is closed on public holidays and between Christmas and New Year.

Alexander Fleming Laboratory Museum -- Alexander Fleming's laboratory today


No wheelchair access because the museum is in its original site which is accessed by stairs. It is in a historic grade two listed building which means there are limitations to how we can renovate, the museum is difficult to adapt to modern standard.

For those unable to visit in person, we offer this 360 tour

Educational visits

Schools and universities are given presentations on the discovery of penicillin in Fleming’s laboratory tailor-made to their ages, attainment levels and interests. Staff will also visit schools.

To arrange a group visit

To arrange a visit or for further information contact Kevin Brown, trust archivist and Alexander Fleming Laboratory Museum curator on 020 3312 6528 or email

Awards and recognitions

• In 1999, the museum was declared an International Historical Chemical Landmark by American Chemical Society and the Royal Society of Chemistry
• San Marino Idea Award for penicillin as one of the five greatest advances of the 20th century
• In 2000, it received an award for The Times for penicillin as a national millennium treasure
• In 2023, the museum was the first designated World Origin Site
• The museum is a member of the London Museums of Health and Medicine.

Fleming Trail

Download a walking tour of Fleming related sites in London

• English version
• Italian version
Spanish version

Volunteers wanted 

We are looking for a volunteer museum guide for the Alexander Fleming Laboratory Museum. The role of volunteer museum guide includes:

• Welcoming guests
• Giving short talks on the story of penicillin
• Serving in the museum shop.

All volunteers will be fully trained and do not require any previous scientific or medical knowledge.

If you are interested in applying, please contact: Kevin Brown, trust archivist and Alexander Fleming Laboratory Museum curator on 020 3312 6528 or email