Background: Developing countries seek to eliminate external debt problems towards financial obligations with a view of alleviating the debt burden to avert economic volatility in the context of debt accumulation. Since the beginning of the 1970s, developing countries, including Algeria, have experienced rapid growth in external debt accumulation in an effort to finance domestic deficits and not enter into economic recession. All these reasons ignore the topic of external debt as an interesting topic of study. This study attempts to analyse and measure some of Algeria's external debt indicators during the study period. Purpose: This research paper focuses on identifying the determinants of external debt in Algeria. Methods: The study utilized the autoregressive distributed lag (ARDL) model and cointegration test to analyze both short- and long-term relationships among the study variables from 1990 to 2021. Results: The findings show that the exchange rate and government spending significantly and positively impact external debt in the long run, whereas GDP per capita and foreign direct investment are significantly negatively correlated with external debt. The short-term results align with those of the long term. Conclusions: The paper advises that the Algerian government and other developing countries should assess their foreign debts, rationalize government spending, diversify their economies, and enhance their investment climates.