Document And Entity Information	3 Months Ended
	Dec. 29, 2012	Jan. 17, 2013
Document and Entity Information [Abstract]
Entity Registrant Name	INSTEEL INDUSTRIES INC
Document Type	10-Q
Current Fiscal Year End Date	--09-28
Entity Common Stock, Shares Outstanding		17,745,410
Amendment Flag	false
Entity Central Index Key	0000764401
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Well-known Seasoned Issuer	No
Document Period End Date	Dec. 29, 2012
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q1