Document and Entity Information - USD ($)	12 Months Ended
	Jul. 31, 2015	Oct. 09, 2015	Jan. 31, 2015
Document And Entity Information
Entity Registrant Name	GENEREX BIOTECHNOLOGY CORP
Entity Central Index Key	0001059784
Document Type	10-K
Document Period End Date	Jul. 31, 2015
Amendment Flag	false
Current Fiscal Year End Date	--07-31
Is Entity a Well-known Seasoned Issuer?	No
Is Entity a Voluntary Filer?	No
Is Entity's Reporting Status Current?	Yes
Entity Filer Category	Smaller Reporting Company
Entity Public Float			$ 12,561,384
Entity Common Stock, Shares Outstanding		859,223,422
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2015