The emission rates of styrene monomer from standard and lowstyrene-emission (LSE) resins were determined during the hand lay-up molding of reinforced polyester. The evaporation tests were carried out in controlled laboratory conditions by using 0.165 m2 laminate. The emission rate was highest in the rolling phase, ranging from 59 to 79 mg/s/m2. The emission rate of styrene with LSE resin was 4-14 percent lower than that of standard resin. The use of LSE resin reduced the total evaporation of styrene 30-60 percent compared to standard resin. This is due to the fact that LSE resin has a lower evaporation rate in the period between the rolling and curing. The evaporation rates obtained by the gravimetric evaporation test do not include the rolling period and should not be used to estimate the emission rate of styrene in actual molding operations.