Surges and reversals of short-term foreign liabilities are often held responsible for instabilities in international financial markets. Yet, empirical evidence on the factors determining the maturity of capital flows is scant. This article analyses the determinants of foreign assets of German banks for a panel of up to 73 countries for the years 1985-1997. Cross section estimates show that short- and long-term assets are highly correlated with foreign trade links, which are more important in explaining claims on banks versus claims on non-banks. The presence of financial centres likewise has a positive impact throughout. Evidence on the importance of exchange rate volatility is more mixed.