Stihl dominates the market for chainsaws in North America, and while most Stihl saws have a good reputation for quality, there have also been recalls for mechanical problems. To find out whether your chainsaw is included in a recall, you need to know the serial number. You will also need it if you are claiming any repairs under your manufacturer's warranty. Writing down the serial number also helps protect you in the event that your chainsaw is stolen; with a serial number you will be able to claim it back if the police recover it.
Standard Serial Number Location
Set the chainsaw down on a workbench and turn the chainsaw so that the tip of the chain is pointing towards you. Examine the saw's housing just to the right of the point where the chain meets the body of the saw. You should find a decal with a barcode and a number embossed in the plastic of the housing. Look closely at the decal if there is one. The serial number will be printed just below the barcode. Record the number embossed into the housing if you can't find the number on the decal or the decal has worn off. The embossed number is also the serial number.
Other Serial Number Locations
Turn the saw over and search the plastic of its housing for small embossed numbers. The large numbers printed in black are the model numbers, not the serial number. The serial number will be somewhere on the housing; numbers on the chain or on individual parts are part numbers, used to order spares from Stihl.
Checking Your Manual
Some, but not all, Stihl chainsaw manuals indicate where to find the saw's serial number. Depending on when the saw was made, the manuals take different formats. A good place to start looking is the last page, which has ordering information for parts and may describe the location of your serial number. If you need to find the manual itself, the Stihl website has many available for free download. If yours isn't offered, you can order a print copy from the same page.
Asking the Seller
If you still can't find the serial number of your saw, it can be worth contacting the store that originally sold it to you. Some stores record serial numbers and names of purchasers for warranty purposes.