When you're first playing the violin, you made it was so you're always having to tune your instrument. No matter how much you pay for a violin or how high quality it's supposed to be, you're going to have to consistently tune your instrument. This is very common for a new violin And a violin that hasn't seen action in a while. Sometimes, this can be because the pegs in the violin have become too loose. With new violins, it may take just a couple of days for the instrument to stay in tune. Other violins may need a few hours of playing to get into tune. You may find that you have to retune your violin that every so often, or maybe even after every 10 minutes. And this can be incredibly frustrating, especially if you don't feel confident in your tuning abilities. Also, if you just put new strings on your violin, it can take some time for the strings to get used to being on your instrument. You'll need to go through the process of breaking in your strings by playing them repeatedly over a period of several days or several weeks for them to get completely broken in. But, if none of this applies to you, and you find your violin is still constantly falling out of tune, take it to a repair shop. There may be a chance that the pegs on your violin aren't properly fitted, or they need more pressure applied to them.