Graduated in medicine from Uppsala University in 1968. Received doctorate in 1975 with a thesis on children's accidents and became a Research Fellow in Social Medicine. Currently lives in Lund where he has previously worked as a School Medical Officer in underpriviliged neighbourhoods Rosengård and Kävlinge, and writes books on the subject of children and parenting.

Executive board member of Save the Children Sweden 1982-1986. During this time Lars H. Gustafsson set up Save the Children Sweden's activities in Beirut and served as the organisation's representative on the Geneva-based working group drawing up the UN Convention on the Rights of the Child. Vice-chairman of Save the Children Sweden and a member of the Swedish committee of UNICEF in the early 1990s. Also served as national chairman of the Swedish Home and School Association for four years.

Author of over ten books on children, including Leva med barn (Living with Children, 1983) and Lotsa barn (Guiding Children, 2000) and Se barnet, se dig själv! (See the Child, See Yourself!, 2004). He has also written about refugee children and war in Barn i krig (Children in War, 1987) and Våga lyssna - att möta flyktingbarn (Daring to Listen - Meeting Refugee Children, 1990). Has also written about views on life and work ethics. His latest books are En läkares samvete (The conscience of a doctor, 2006) och När musiken tystnar (When the music stops, 2007).

Lars H. Gustafsson received the Janusz Korczak International Book Award in 1998 from the Polish section of IBBY (International Board on Books for Young People) for his book Upptäcka livet (Discovering Life). On a beautiful summer's day in 1995, he was personally presented by Astrid Lindgren with an award sponsored by the Astrid Lindgren's World Scholarship, awarded to "an individual who, in the spirit of Pippi Longstocking, uses his/her knowledge and power to help children and make them happy".