"The most important phase of a project is the planning phase, not the execution." Do you agree with this statement? Why or why not?

In Project Management, Planning is the key factor while execution is one of the important component. Good Planning,good execution and bad planning result in bad execution.Although there are risks but in good planning risk management is one of the important component.I totally agree, good planning is important for the success of a project.

It is always best to plan before you start.  It gives you the opportunity to analyse possible threats to the project, which you can then create a contingency plan.  It does not only save you time, but also money. Planning also gives you the necessary data to budget more closely and allocate money for potential risk.  If the risk doesn't materialize, the money can be returned to investor or used as an incentive to employees to complete project ahead of time.

you cant have a good execution if you dont have good planning. 

Both are important but sequence is planning 1st & execution 2nd to gether sucess

In most scenarios this is applicable, since the resources invested in planning phase will reduce dramatically the execution expenses. However, In some cases, the project nature is variable, and needs constant update/change, under these circumstances, there will be more benefit in being pro-active and react quickly rather than waiting a plan to be in place.

I agree, without proper planning you are setting up the project to fail as there will be no clear guidelines regarding scope, budgets and resources including timelines for when each activity in the project should be performed

I don't Agree, both planning and execution are important, project success is determined in planning well and good execution, if planning is well and executions is not the project might fail.

yes agree, project planning is the first step. before executing we should have a plan to work. it will help us to work in the right path with out any obstruction and we can be well prepared and act according knowing the difficulties to overcome easily.

Planning phase is as important as blood for body, if planning is improper you will never get your desired results. After planning execution complete its part in achieving organization goals.

yes it is the most important phase it starts when the project starts and finish until the handing over not only the execution. To execute and achieve the milestones you should know the constraints and the solution for them before, which only can be done when you have spend a good and proper time in planning phase.

Yes of course Planning is the most important. well planned project is executed with success.