This paper uses transaction-level data from Thailand to study concentration, specialization, and fragility of export activities. The paper shows that although exports have been an integral part of the development strategy of the country for several decades, direct engagement in international trade through exports is a rare activity. Export firms are different from their nonexport counterparts. Export activities are also extremely concentrated. There is a great deal of churning in Thai exports and exporting relationships are highly fragile. The findings highlight some cautions from a micro perspective about an export-oriented development strategy, particularly regarding concentration and vulnerability.