Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2021	Mar. 01, 2022	Jun. 30, 2021
Document Information [Line Items]
Entity Central Index Key	0000101295
Entity Registrant Name	UNITED GUARDIAN INC
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2021
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2021
Document Transition Report	false
Entity File Number	1-10526
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	11-1719724
Entity Address, Address Line One	230 Marcus Blvd
Entity Address, City or Town	Hauppauge
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	11788
City Area Code	631
Local Phone Number	273-0900
Title of 12(b) Security	Common Stock, $.10 par value
Trading Symbol	UG
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Filer Category	Non-accelerated Filer
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Public Float			$ 68,960,700
Entity Common Stock, Shares Outstanding		4,594,319
Auditor Name	Baker Tilly US, LLP
Auditor Location	Uniondale, NY
Auditor Firm ID	23