The 6th Scientific and Career Day of the IARC Early Career Scientists Association (ECSA) was held at IARC on 23 May 2019. In the morning, after a welcome from IARC Director Dr Elisabete Weiderpass, there were oral presentations, lightning talks, and poster presentations. In the afternoon, there was a team building exercise, followed by a career development workshop and a career panel session with presentations from invited speakers. Some of IARC’s early career scientists explain why the day is important and what they gained from it.