EXHIBIT 12.1

COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES

The following table sets out the computation of Tenaris’s ratios of earnings to fixed charges for each of the five years ended December 31, 2009, 2008, 2007, 2006 and 2005 and for the nine month period ended September 30, 2010, calculated in accordance with International Financial Reporting Standards as issued by the International Accounting Standards Board and adopted by the European Union.

	Nine month period ended, September 30,			Year Ended December 31,
	2010			2009			2008			2007			2006			2005
				(Thousands of U.S. dollars, except ratios)
Earnings
Income from continuing operations before equity in earnings of associated companies and income tax		1,077,336			1,661,907			2,894,626			2,716,642			2,743,034			1,820,472
Fixed charges		72,634			151,173			247,960			311,937			105,532			75,763
Amortization of capitalized interest		163			234			246			230			211			209
Distributed income of equity investees		13,732			11,420			15,032			12,170			—			59,127
Other types of interest on non-third party indebtedness		3,583			4,982			5,885			5,966			3,666			584
Subtotal		1,167,448			1,829,716			3,163,749			3,046,945			2,852,443			1,956,155
Interest capitalized		(1,062	)		(975	)		—			—			—			—
Preference security dividend requirements of consolidated subsidiaries		(17,579	)		(19,399	)		(52,718	)		(23,538	)		(9,466	)		(21,991	)
Total earnings		1,148,807			1,809,342			3,111,031			3,023,407			2,842,977			1,934,164
Fixed charges
Interest expense		53,963			130,738			195,138			288,302			95,827			53,504
Capitalized expenses related to indebtedness		1,062			975			—			—			—			—
Estimate of the interest within rental expense		30			61			104			97			239			268
Preference security dividend requirements of consolidated subsidiaries		17,579			19,399			52,718			23,538			9,466			21,991
Total fixed charges		72,634			151,173			247,960			311,937			105,532			75,763
Ratio of earnings to fixed charges		15.8			12.0			12.5			9.7			26.9			25.5