The presented research was aimed at analysing the emission characteristics of a domestic heating boiler fed with Virginia mallow pellets (Sida her-maphrodita Rusby) and wood pellets available on the market. A 32 kW boiler with automatic fuel load adapted to wood pellets combustion was used in the research. The installation used in the research was a typical installation used to heat single-family houses. Timelines of changes in O2, CO, CO2, NO, NOX, and SO2 concentrations were registered at the boiler¶Voutlet throughout the study. Analyses of mallow pel-lets and wood pellets combustion in a boiler with au-tomatic fuel load adapted to wood pellets combus-tion showed that CO, NO, NOX and SO2 emissions were higher during mallow pellets combustion.