Document and Entity Information - shares	3 Months Ended
	Oct. 31, 2016	Dec. 29, 2016
Document And Entity Information
Entity Registrant Name	GENEREX BIOTECHNOLOGY CORP
Entity Central Index Key	0001059784
Document Type	10-Q
Document Period End Date	Oct. 31, 2016
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 Common Stock, Shares Outstanding		908,541,475
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2016