The number of posts at risk has not been finalised but D&W denied that any of its 82 partners were under threat.
Legal sources suggested property and corporate are likely to bear the brunt of the changes with more positions at risk in Scotland than in London.
A statement from D&W said: "We can confirm that the firm has undertaken a preliminary assessment of the nature and level of demand for its services over the next few years.
"Following this review we have concluded that it will be necessary to reshape some practice areas to reflect the anticipated business needs. Regrettably, this process of realignment will likely lead to the loss of some positions."
The announcement comes after some aggressive growth tactics from the firm in recent months.
In January D&W took on a five-strong banking team from Stephenson Harwood in London.
Then earlier this month it announced the opening of a new office in Aberdeen headed by corporate partners Douglas Crawford and David Davidson.
Last year the firm, which has a £62 million turnover, decided not to merge with the smaller London-based Bircham Dyson Bell.
The size of job losses this time is not expected to be as high as in February 2009 when D&W said it was making 50 people redundant while also asking some of its trainees to defer their placements.
Several Scottish firms have cut jobs during the recession and recovery.
Some put staff on shorter working weeks, temporarily reduced pay and offered unpaid holidays as an alternative to redundancy.
However, McGrigors shed around 40 people, Semple Fraser and DLA Piper 20 each with Burness, Morton Fraser, Brodies and Tods Murray among the others cutting posts.
The commercial law sector has seen a declining rate of activity in the once buoyant corporate and commercial property sectors which had led to pressures on fees and competition for work.
This year McGrigors agreed one of the biggest mergers in recent years when its partners agreed to join with Pinsent Masons.