In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu `alaykum wa-rahmatullāhi wa-barakātuh.
Smoking cigarettes is harmful to one’s health. Nevertheless, if one is in a state of wudu and
smokes that does not invalidate the wudu. The foul odour that emanates after smoking should be
rinsed from the mouth before entering the Masjid. If necessary apply itar to replace it.
Rasulullah (Sallallahu Alaihi wa Sallam) prohibits the person who has eaten raw garlic or onion
from entering the Masaajids until the odour fades. (Tirmidi Vol.2 page 3. Edition HM Saeed )
And Allah knows best.
Mufti Saeed Ahmed Golaub Islamic Solutions Jamaica