Document And Entity Information - shares	9 Months Ended
	Feb. 28, 2018	Apr. 16, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	BIOMERICA INC.
Document Type	10-Q
Current Fiscal Year End Date	--05-31
Entity Common Stock, Shares Outstanding		8,651,961
Amendment Flag	false
Entity Central Index Key	0000073290
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Smaller Reporting Company
Entity Well-known Seasoned Issuer	No
Document Period End Date	Feb. 28, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q3