Works great in the Samsung Galaxy S3 phone. I purchased one for my phone and one for my son's phone and they both work great! We've had no problems with either card. My son loves that he was able to put his whole music library, several translator apps and bible versions, along with several movies on his phone to take with him on a mission trip to Peru and still had room to store thousands of photos he took while there. Being able to use a card like this is one of the main reasons I switched from an iPhone to an S3. Love it!