Hornby said expects trading for the year to March to be at the low end of analysts' expectations, due in part to muted demand in the pre-Christmas period.
The firm is concerned that Sterling's depreciation against both the Euro and the US dollar could become an issue in coming months.
"Unless sterling strengthens from its current rate, we would anticipate a material erosion to our margins in the year to 31st March 2010," said that firm in a statement.
It added that it was considering raising prices to mitigate those effects. But said it expected a strong finish to the current financial year.
"Overall trading in December was significantly above the previous year. We continue to operate within our banking facilities."