Vasudeva Dwadashi or Vasu Dev Dwadasi is the Dwadasi day dedicated to Lord Vasudeva (Lord Sri Krishna). Vasudev Dwadasi falls on Ashada Shudda Dwadasi, just a day after Shayana Ekadasi or Deva Sayani Ekadashi. In 2012, the date of Vasudeva Dwadashi Vratam is July 1.
According to Puranas, Lord Vishnu represents Ekadasi and Goddess Mahalakshmi represents Dwadasi.
On Vasudeva Dwadasi, devotees of Sri Krishna recite Krishna stotras and worship Lord Sri Krishna. Some devotees donate cow to please Lord Krishna. Godaanam (Donating cow) is the most meritorious deed performed on Vasu Deva Dwadasi. Performing puja to cow is the most recommended ritual to do on Vasudev Dwadashi. Vasudeva Dwadasi is also observed as Vamana Dwadashi.