Their website says this: MSC Cruises has introduced throughout its fleet a “Clean Air” policy, which will allow both smokers and non-smokers to enjoy their holidays on board in mutual respect.
After the introduction of the ‘Clean Air’ policy, the trials of the extensive smoke-free zones have received general approval of passengers.
We have eliminated smoking in all areas where non-smokers and smokers would have shared the same spaces.
We assigned a few rooms where smokers are welcome, but the majority of indoor spaces are now non-smoking.
On all MSC vessels, smoking is therefore only allowed indoors in the Cigar Rooms, the Casinos and in one dedicated lounge. Passengers can also smoke outside, on one side of the sun deck, but no smoking is allowed in cabins or on balcony cabins.
The rest of the ships is therefore totally smoke-free, for the benefit of non-smokers.
Thanks to the Clean Air Policy, MSC Cruises has therefore managed to satisfy both smokers and non-smokers by having a 90% smoke-free ship.