The no-frills carrier, which is on a revival path under the ownership of Ajay Singh, would be wet leasing the three aircraft for a period of three months.
Sources said SpiceJet plans to lease a total of seven Boeing 737 aircraft by end of this month. While three would be taken on wet lease from Czechoslovakian company TVS, the remaining four would be on dry lease basis, they added.
In wet lease, besides aircraft, pilots and crew are included whereas there is only aircraft in dry lease.
At present, SpiceJet has 17 Boeing 737s and 15 Bombardier Q400s in its fleet.
The carrier has already scaled up the number of its flights to 270 in the current summer schedule from 210 flights operated in the last winter schedule.
SpiceJet, which saw ownership change in February after going through financial turmoil, saw quitting of a number of pilots last year.
Mr Singh took over the reins of SpiceJet from erstwhile promoter the Maran family as part of the airline's revival plan.
Under the deal, the Maran family transferred its entire 58.46 per cent holding in the no-frills carrier to Singh, who co-founded SpiceJet along with the then majority stakeholder Bhupendra Kansagra in 2005.
He, however, divested almost his entire stakes to Kalanidhi Maran-owned Sun Group in 2010 along with Kansagra, but retained a minuscule 1.85 per cent with him.
Currently, Mr Singh holds 60.31 per cent in SpiceJet after acquiring the entire 59.46 per cent from Marans.