"We had a useful discussion which lasted over an hour," a European diplomatic source quoted Ashton as saying after the meeting held in the Russian ambassador's residence in Madrid.
The Russian foreign minister then met Spanish Prime Minister Mariano Rajoy and Spanish King Juan Carlos.
Lavrov is scheduled to meet Spanish Foreign Minister Jose Manuel Garcia Margallo on Wednesday.
Earlier on Tuesday, Lavrov said that threats of sanctions against Moscow were counter-productive and would not change its position on the Ukraine crisis.
"Our position is honest and… will not change," he told a news conference in Tunisia, where he was on an official visit.
"We have always opposed the policy of unilateral sanctions. I hope our partners understand that such actions are counter-productive."
Western powers have been wrestling with how to respond to Russia's threat to use force against Ukraine, where president Viktor Yanukovych was driven from power following three months of protests that culminated in days of carnage.
EU foreign ministers warned Moscow on Monday to de-escalate or risk sanctions, including the suspension of long-running talks on easing EU visa requirements for Russian citizens. EU leaders are meeting to discuss the crisis on Thursday.
Washington has suspended military cooperation with Moscow, and the Kremlin has responded to US warnings, saying sanctions against Russia "would end in a crash for the financial system of the United States".