The potential health effects of fine and ultrafine particles are of increasing concern. A better understanding of particle characteristics and dispersion behavior is needed. This study aims at characterizing spatial and temporal variations in fine and ultrafine particle dispersion after emission from a model source in an experimental house. Particles emitted by an incense stick burning for 15 min were characterized. Number concentration, specific surface area and mass were measured. Partial chemical analysis of particles was also realized. Near the burning incense stick, the maximum concentration was 25,500 particles/cm(3); the indoor PM(2.5) concentration reached 197 microg/m(3), and the specific surface area concentration was 180 microm(2)/cm(3). The estimated incense smoke density was 1.1 g/cm(3). Time of Flight Aerosol Mass Spectrometer measurements indicated that the organic fraction was predominant in the aerosol mass detected, and other minor components identified were K(+), NO(3)(-), and Cl(-). The combustion of an incense stick in the living room was associated with significant modifications of the concentrations of particles measured in the different rooms of the house. This demonstration of pollution by particle dispersion by a model source of moderate intensity may have significant implications in terms of assessment of indoor exposure to such particles. Practical Implications The particles emitted in a domestic environment by a source of moderate intensity such as burning incense disperse throughout the house, even in rooms with closed doors and in rooms as far away as the next floor. This dispersion has significant implications in terms of evaluating human indoor exposure to fine and ultrafine particles.