Massachusetts Rules of Professional Conduct Rule 1.3: Diligence
A lawyer shall act with reasonable diligence and promptness in representing a client. The lawyer should represent a client zealously within the bounds of the law.
Adopted June 9, 1997, effective January 1, 1998.
 A lawyer should pursue a matter on behalf of a client despite opposition, obstruction or personal inconvenience to the lawyer, and may take whatever lawful and ethical measures are required to vindicate a client's cause or endeavor. A lawyer should act with commitment and dedication to the interests of the client and with zeal in advocacy upon the client's behalf. However, a lawyer is not bound to press for every advantage that might be realized for a client. A lawyer has professional discretion in determining the means by which a matter should be pursued subject to Rule 1.2. A lawyer's work load should be controlled so that each matter can be handled adequately.
[1A] It is implicit in the second sentence of the rule that a lawyer may not intentionally prejudice or damage his client during the course of the professional relationship.
 Perhaps no professional shortcoming is more widely resented than procrastination. A client's interests often can be adversely affected by the passage of time or the change of conditions; in extreme instances, as when a lawyer overlooks a statute of limitations, the client's legal position may be destroyed. Even when the client's interests are not affected in substance, however, unreasonable delay can cause a client needless anxiety and undermine confidence in the lawyer's trustworthiness.
 Unless the relationship is terminated as provided in Rule 1.16, a lawyer should carry through to conclusion all matters undertaken for a client. If a lawyer's employment is limited to a specific matter, the relationship terminates when the matter has been resolved. If a lawyer has served a client over a substantial period in a variety of matters, the client sometimes may assume that the lawyer will continue to serve on a continuing basis unless the lawyer gives notice of withdrawal. Doubt about whether the client-lawyer relationship still exists should be clarified by the lawyer, preferably in writing, so that the client will not mistakenly suppose the lawyer is looking after the client's affairs when the lawyer has ceased to do so. For example, if a lawyer has handled a judicial or administrative proceeding that produced a result adverse to the client but has not been specifically instructed concerning pursuit of an appeal, the lawyer should advise the client of the possibility of appeal before relinquishing responsibility for the matter.
Corresponding ABA Model Rule. Identical to Model Rule 1.3 with the addition of the clause at the end of the Rule.
Corresponding Former Massachusetts Rule. DR 6-101 (A) (3); DR 7-101.