Where to enter deduction for tuition?

[misterno123]

My son has autism and he is attending this private school to which I pay tutition

I have been told that if his pediatrician writes a letter that special needs school would benefit him then I can deduct the tuition I paid to the school.

Where do I enter this deduction in my taxes? Which form in 1040?

[Hal_Al]

It would be entered as medical expenses.  Medical expenses are only deductible as an itemized deduction subject to a 7.5% of AGI threshold.  Itemized deductions go on Schedule A.