Les Wallerstein

I am an attorney with a master’s degree in psychology, committed to the least adversarial practice of law possible. I had 20 years of experience working as a psychotherapist with individuals, couples, families and groups before becoming a lawyer in 1990.

I served as president of the Massachusetts Council on Family Mediation in 2001, and was the founder and editor of MCFM’s Family Mediation Quarterly from 2002 – 2013. I have been certified as a divorce mediator by MCFM since 1996.

In 2000 I was a founding member of the Massachusetts Collaborative Law Council, and served as treasurer for two years. Between 2003 and 2006 I was a co-founder and co-editor of MCLC’s Collaborative Law Journal, and have helped teach collaborative law.

My family practice has always concentrated on mediating agreements. In 1996 I stopped representing plaintiffs or defendants in court. I believe it is especially important to avoid the ravages of litigation when children are involved whenever possible.

I still represent clients in adversarial actions as settlement counsel. Our work focuses exclusively on negotiating agreements. When a mediated or collaborative agreement is not possible, I refer clients to lawyers who specialize in litigation.

While collaborative legal representation is an integral part of my work, mediating family disputes remains at the heart of my practice.


Massachusetts Council on Family Mediation
Member: 1992 – present
Board of Directors: 1993 – 2019
President: 2001 – 2002
Founder & Editor, Family Mediation Quarterly: 2002 – 2013
Director Emeritus: 2022 – present

Massachusetts Collaborative Law Council
Founding Member: 2000
Board of Directors: 2000 – 2004
Treasurer: 2000 – 2002
Co-founder & Co-editor, Collaborative Law Journal: 2003 – 2006
Member: 2000 – 2010

Massachusetts Bar Association
Member: 1990 – present
Family Law Section: 1998 – present

National Lawyers Guild
Member: 1990 – present

Aids Action Committee of Massachusetts
Volunteer Attorney: 1992 – present


Certified Divorce Mediator
Massachusetts Council On Family Mediation: 1996 - Present

Principal Psychologist
Commonwealth of Massachusetts: 1974

Licensed & Certified Social Worker
Commonwealth of Massachusetts: 1982

Justice of the Peace
Commonwealth of Massachusetts: 2008 - Present

Free Divorce Mediation Consultations

Free, one-hour consultations are only available on weekdays from 9:00 AM to 4:00 PM, and are only offered to couples interested in divorce mediation IF neither spouse has a court action pending against the other… and no legal actions have been filed in the past 12 months.