Document And Entity Information - shares	6 Months Ended
	Mar. 31, 2016	May. 11, 2016
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2016
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	Q2
Entity Registrant Name	BIOANALYTICAL SYSTEMS INC
Entity Central Index Key	0000720154
Current Fiscal Year End Date	--09-30
Entity Filer Category	Smaller Reporting Company
Trading Symbol	BASI
Entity Common Stock, Shares Outstanding		8,107,558