Oilseeds such as flax, canola, safflower, soybean and sunflower, which are annual plants, provide the world’s major source of vegetable oils, although the highest oil yield comes from oil-bearing tree fruits. One of the most popular oil seeds is safflower (<em>Carthamus tinctorius</em> L.), which belongs to the Asteraceae family. Due to the ability of this plant to grow in dry and semi-dry conditions, safflower oil has the potential to be a commercially profitable product in Iran. Seasonal populations of safflower capsule flies were studied in Kohgiluyeh safflower farms, Iran, from March to May in 2008 and 2009. Four yellow sticky traps were used to monitor populations of fruit flies in the safflower farms. Traps were checked once a week during the sampling period. The traps were emptied weekly into insect collection vials containing 70% ethanol. Data were analysed with a two-way ANOVA. The relation between abiotic factors and species abundance was analysed with multiple linear regression. The results emphasized that <em>Acanthiophilus helianthi</em> was the most serious pest of safflower under the ecological conditions found in Gachsaran, being present in the field throughout three months of the year (March to May). <em>Chaetorellia carthami</em> was present in safflower fields from March to May, but in significant numbers only during April and May. <em>Terellia</em> <em>luteola</em> was present in safflower fields from March to May and in significant numbers only in late April, it does not seem to be a serious pest in safflower farms under Gachsaran’s ecological conditions.