Organisers are set for their biggest-ever attendance of more than 5000 for the event which is now in its third year.
And the play, which includes a re-enactment of Jesus' crucifixion, is also expected to be blessed with good weather for the first time - which it is hoped will encourage even more people to attend.
The play, under the dramatic backdrop of Edinburgh Castle, will take place on six different locations within the Gardens, including the Ross Bandstand and the Scottish American War Memorial.
It is to be a shortened version of the day-long Life of Jesus passion play that takes place at Dundas Castle this June.
Suzanne Lofthus, the play's director, expects turnout to be significantly above the 3700 who attended last year following the cancellation of the Easter Parade.
She said: "Our target that we have been working towards is 5000 and it would be great if we achieved that.
"We're set up for that, with all the security and stewarding to allow for it, and it would be a real achievement if we got it. This will be the first year that there is not an Easter Parade so it might well help us and make this the main family event."
It is also hoped that some of the 6500 people travelling to the city for the Resurrection 07 event on Easter Sunday at Ingliston will attend the play and significantly boost numbers.
"There will be a lot of people at Resurrection and we're hoping they will come to see the play too. We're hoping for good weather as well and that should make a big difference.
"The first year we did it was freezing cold and last year it rained."
For the first time, an Edinburgh-based actor will play the lead role as Jesus.
Starting at 2.30pm, Sciennes-based Duncan Rennie will be joined by 60 other cast members made up of adults and children who have volunteered.
All of the cast in the two-hour performance are from the Edinburgh, Lothians and Fife area, and were recruited through posters in youth groups, community centres and churches.
Mr Rennie, 30, said: "Princes Street Gardens is a very different location to the other venues we've had the play in, Dundas Castle and Kelvingrove Park.
"At Dundas the owner has sculpted some of the grounds to cater for the play, whereas Princes Street Gardens is obviously as it is.
"But strangely, it naturally fits and is perfect for the play. The backdrop of the Castle, the layout of the Gardens and the different parts within it are just fantastic."
The play will take up the story from the point where Jesus is an adult, rather than when he is born as is the case in the Dundas Castle version.
Gill Cook, the producer, said: "The drama takes us on a journey with Jesus and his disciples. We follow them from Galilee to Jerusalem.
"It is our hope that the audience will experience something of the power and truth of this drama as they watch our production."
The play starts at 2.30pm tomorrow, and entry is free.