Cleaning smoke off of walls is a nasty job. Whether it's cigarette smoke, accumulated smoke from candles or smoke from a kitchen fire, the method is pretty much the same: combine smoke- and oil-cutting cleaners and some hard work.
First assess the situation. It may be impossible to completely clean smoke damage from flat-painted walls. If the walls bear a satin or semigloss paint, it is possible to clean them, unless the smoke damage is severe.
Clear the area (or as close as possible). Fill a bucket with TSP cleaner, about 1 heaping tablespoonful per gallon of warm water. Put on rubber gloves, because TSP can be very harsh and irritating to your skin.
Starting at the bottom of the wall, apply and wipe on the TSP with a large sponge, such as you might use for washing a car. Work your way up the wall, going in sections. You may have to repeat this process several times, depending on the severity of the smoke damage.
Avoid soaking the wall with too much water. If you get the underlying sheetrock wet, you could damage it to the point where drywall repair is necessary. Also try not to let water run down between the baseboard and the wall. This could both promote mildew growth and loosen the flooring along the baseboard.
Rinse the walls thoroughly with clear water, again working from the bottom up. As with the washing, it may take several rinsings to get the wall clean.
Watch for dulling of painted walls. In a strong solution, TSP and similar cleaners may permanently dull painted surfaces. If this happens and you have cleaned all the smoke residue from the wall, you probably do not need to prime the walls before repainting with one quick coat.
There are products available specifically for cleaning smoke damage, although TSP works awfully well. Check with your local home store for different cleaners. If the smoke damage is considerable, consider contacting your homeowners'- or renters'-insurance carrier and filing a claim.
True TSP may not be available in all states, because it is a fairly harsh chemical. There are some very effective alternatives, however. If the wall is painted with flat paint, it will probably be impossible to clean it successfully. If that is the case, get as much smoke residue off the walls as possible, prime and repaint. If the smoke damage is on wallpaper, call the manufacturer or the store where you bought it for specific cleaning instructions.