The invention provides an oil well pipe for expandable tubular applications excellent in post-expansion toughness and a method of manufacturing the oil well pipe. The oil well pipe for expandable tubular applications comprises, in mass%, C: 0.03 to 0.14%, Si: 0.8% or less, Mn: 0.3 to 2.5%, P: 0.03% or less, S: 0.01% or less, Ti: 0.005 to 0.03%, Al: 0.1% or less, N: 0.001 to 0.01%, B: 0.0005 to 0.003%, optionally comprises one or move of Nb, Ni, Mo, Cr, Cu and V, and further optionally comprises one or both of Ca and REM, satisfies the relationship A =" 2".7 C + 0.4 Si + Mn + 0.45 Ni + 0.45 Cu + 0.8 Cr + 2 Mo ¥ 1.8, has a balance of iron and unavoidable impurities, and is formed of tempered martensite structure. The manufacturing method according to the invention is characterized in subjecting a steel stock pipe of the foregoing composition to hardening from a temperature range of Ac 3 point + 30 °C or greater and to tempering at a temperature of 350 to 720 °C.