The figures, released by HMRC, show there was an increase in Welsh exports to both EU and non-EU counties, up £53million (one per cent) and £575million (eight per cent) respectively.
During the first quarter of 2012 there was a small increase (£14million) in the value of Welsh exports on the previous quarter, compared to a 3.3 per cent fall in the value of UK exports as a whole.
Mrs Hart said:
"Exports can be notoriously volatile, but these latest figures show Welsh exports holding up well, and indeed showing a small improvement, in this most challenging global climate.
"This latest five per cent increase in Welsh exports is to be welcomed. Between 1999 and the four quarters up to the first quarter of 2012, Welsh exports have more than doubled (107.7 per cent), compared to a 71.3 per cent increase for the UK as a whole.
"However we are stepping up our efforts to further encourage Welsh-based companies to pursue overseas trade and investment opportunities by leading an extensive programme of overseas trade missions to the Far East, North America, Gulf States and other key markets over the next 18 months."