The study blames a lack of long-term success on companies' inability to prepare and train managers to be effective change leaders.
It found more than half (55%) said their change management initiatives met initial objectives, but only 25% are able to sustain gains over the long term.
These initiatives can range from programme or policy changes to business transformation and mergers and acquisitions.
"Most companies are having a difficult time keeping the momentum of their change management initiatives going," said Nicola Cull, a senior change management consultant at Towers Watson.
"The organisations that are able to sustain change over time are those that focus on the fundamentals that we know drive successful change: communication, training, leadership engagement and measurement.
"And despite nearly uniform acceptance that these are the key drivers of change, the companies that are not good at them are not getting any better."
The study of more than 250 large and mid-sized global employers found despite 87% claiming to train their leaders to manage change, only 22% said their training was effective.
Cull said: "Managers are a catalyst for successful change. Now is the ideal time for organisations to look at this lingering problem from a new angle, focusing on the manager's role.
"For managers to succeed at spearheading change, companies need to change their approach, train managers more effectively and do a much better job of communicating with them."