Document And Entity Information - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2018	Sep. 01, 2018	Dec. 31, 2017
Document Information [Line Items]
Entity Registrant Name	BION ENVIRONMENTAL TECHNOLOGIES INC
Entity Central Index Key	0000875729
Trading Symbol	bnet
Current Fiscal Year End Date	--06-30
Entity Filer Category	Smaller Reporting Company
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Entity Common Stock, Shares Outstanding (in shares)		25,991,394
Entity Public Float			$ 10.3
Document Type	10-K
Document Period End Date	Jun. 30, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY
Amendment Flag	false