The author describes an annual database of physical infrastructure stocks for a cross-section of 152 countries for 1950-95. The database contains six measures: kilometers of roads; kilometers of paved roads; kilometers of railway lines; number of telephones; number of telephone main lines; and KW of electricity generating capacity. The database includes some measures of infrastructure quality (percentage of roads in poor condition, percentage of local phone calls that are unsuccessful, percentage availability of diesel locomotives, and percentage of electricity lost from the system), but only for recent years. the author examines correlation patterns and reports regressions relating infrastructure stocks to country population, per capita GDP, land area, and the urbanization ration. The relationship between infrastructure and economic growth is examined in a preliminary way. The author reports that: nontransportation infrastructure stocks tend to increase one-for-one with population but increase more than proportionately with per capita GDP; geographic factors (area, urbanization ration) appear to affect the provision of nontransportation infrastructure in poor countries but not in rich countries; transportation infrastructure appears to increase less than proportionately with population, and increases with income only after a middle-income threshold has been reached; and geographic factors seem to influence the length of total roads and rail lines but not of paved roads. Panel unit root tests indicate that the log infrastructure stock per capita series are nonstationary and have a unit root. Cross-section growth regressions show our common worldwide estimated regression results for infrastructure stocks to be stable, long-run relationships. Preliminary regression results suggest that have a greater number of telephone main lines per capita has a positive effect on economic growth.