What’s the most important thing for a project manager to do?

1. Focus on milestones - post planning an during execution

2. Communicate the different items for the project and keep the stakeholders updated on all aspects

3. Cost control for the sponsor

4. Setup quality control on the deliverables

Two key important factors which project managers need to do on a daily basis are communicate and forecast. Communication is key to delivering a successful project be it with stakeholders, peers, subordinates etc. While forecasting is important as the project manager needs to not only think about how the project is moving along, but also ensure that he is able to foretell potential hazards in the project and effectively mitigate these hazards or risks.

Communications, either written or verbally in any formal or informal fashion.

In my point of view, the most important thing the project manager can do "Change Management", that skill can differentiate the best PM. all manager can follow a plan but not many can manage the change.

The Project Manager's key responsibility has to be successfully delivering the objectives and benefits the sponsor expects of the project, or the project stage the project Manager is assigned to.

1. the person in overall charge of the planning and execution of a particular project.