DOCUMENT AND ENTITY INFORMATION	9 Months Ended
	Apr. 30, 2013	Jun. 07, 2013
Entity Registrant Name	GENEREX BIOTECHNOLOGY CORP
Entity Central Index Key	0001059784
Current Fiscal Year End Date	--07-31
Entity Filer Category	Accelerated Filer
Trading Symbol	gnbt
Entity Common Stock, Shares Outstanding		531,525,287
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Apr. 30, 2013
Document Fiscal Period Focus	Q3
Document Fiscal Year Focus	2013