- Man and Gorilla (1949)
- Escape from Yesterday (1950)
- To the Dark Towers (1950)
- The Crime Exterminator (1951)
- The Blue Remembered Hills (1951)
- This is New York (1951)
- Inhumanities (1953)
- The Deveron Secret (1954)
- Beyond Tomorrow (1955)
- The Fox of Norvaag (1955)
- Escape to Danger (1955)
- Shadows of Doubt (1955)
- Dead Man's Island (1956)
- The Silent Intruder (1956)
- Fatal Decision (1957)
- Deadly Safari (1958)
- Secret of the Forbidden Caverns (1958)
- The Key to Power (1959)
- The Lost City (1960)
- The Black Beach (1961)
- Operation North Pole (1962)
- Secret Mission to the Orient (1962)
- Danger Downunder (1963)
- The Golden Cobra (1963)
- Mission to Morocco (1963)
- Escape from Red China (1964)
- Mystery in the Antarctic (1965)
- The Hidden City (1966)
- Peril in Peru (1967)
- Danger in Death Valley (1968)
- Terror in Texas (1969)
- The Curse of the Mummy (1970)
- Monster from the Depths (1971)
- The Robot Invasion (1972)
- The Time Machine (1973)
- The Invisible Man (1973)
- War of the Worlds (1974)
- The First Men in the Moon (1974)
- Twenty Thousand Leagues Under the Sea (1974)
- Journey to the Center of the Earth (1974)
- From the Earth to the Moon (1974)
- Around the World in Eighty Days (1974)
- The Mysterious Island (1974)
- Michael Strogoff (1974)
- The Swiss Family Robinson (1975)
- The Last of the Mohicans (1975)
- The Deerslayer (1975)
- The Prairie (1975)
- The Pathfinder (1975)
- The Pioneers (1975)
- The Pilot (1976)
- The Red Rover (1976)
- The Crater (1976)
- The Sea Lions (1977)
- The Last of the Wicannees (1978)
- White-Fire (1979)
- Bloodfire Quest (1981)
Collections:
- The Langdon E. Longstreth Collection (1968)
- The Best of Langdon E. Longstreth (1971)
- The Secret of the Forbidden Caverns and Other Stories (1974)
Short stories:
- "Man and Gorilla" (1949)
- "Escape from Yesterday" (1950)
- "To the Dark Towers" (1950)
- "The Crime Exterminator" (1951)
- "The Blue Remembered Hills" (1951)
- "This is New York" (1951)
- "Inhumanities" (1953)
- "The Deveron Secret" (1954)
- "Beyond Tomorrow" (1955)
- "The Fox of Norvaag" (1955)
- "Escape to Danger" (1955)
- "Shadows of Doubt" (1955)
- "Dead Man's Island" (1956)
- "The Silent Intruder" (1956)
- "Fatal Decision" (1957)
- "Deadly Safari" (1958)
- "Secret of the Forbidden Caverns" (1958)
- "The Key to Power" (1959)
- "The Lost City" (1960)
- "The Black Beach" (1961)
- "Operation North Pole" (1962)
- "Secret Mission to the Orient" (1962)
- "Danger Downunder" (1963)
- "The Golden Cobra" (1963)
- "Mission to Morocco" (1963)
- "Escape from Red China" (1964)
- "Mystery in the Antarctic" (1965)
- "The Hidden City" (1966