Here are the books he has written and the dates they were published:
The Scarlatti Inheritance, 1971 - Scarlatti
The Osterman Weekend, 1972 - Verinen viikonloppu - film 1983, dir. by Sam Peckinpah, starring Rutger Hauger, John Hurt, Burt Lancaster
Trevayne, 1973 (as Jonathan Ryder, as Robert Ludlum in 1989)
The Rhinemann Exchange, 1974 - Pahan kauppamiehet - NBC television miniseries in 1977
The Cry of the Halidon, 1974 (as Jonathan Ryder)
The Road to Gandolfo, 1975 (as Michael Shepherd) - Marssi Roomaan ja Omahaan
The Gemini Contenders, 1976
The Chancellor Manuscript, 1977 - Vastaisku / Medusan isku
The Holcroft Convenant, 1978 - Verirahat - film 1985, dir. by John Frankenheimer, starring Michael Caine, Anthony Andrews, Victoria Tennant, Lilli Palmer
The Matarese Circle, 1979 - Mataresen merkki
The Bourne Identity, 1980 - Medusan verkko - television film 1988; film 2002, directed by Doug Liman, starring Matt Damon, Adewale Akinnuoye-Agbaje, Franka Potente, Julia Stiles
The Parsifal Mosaic, 1982 - Paholaisen mosaiikki
The Aquitaine Progression, 1984 - Salaliitto
The Bourne Supremacy, 1986 - Medusan isku
The Matlock Paper, 1987 - Omertan laki
The Icarus Agenda, 1988 - Salainen Ikaros
The Bourne Ultimatum, 1990 - Meduusan sinetti
The Road to Omaha, 1992 - Marssi Roomaan ja Omahaan
The Scorpio Illusion, 1993 - Skorpioiden seitti
The Robert Ludlum Companion, 1993 (ed. by Martin H. Greenberg)
The Apocalypse Watch, 1995 - Tuhon veljeskunta
The Matarese Countdown, 1997 - Mataresen tuho
The Hades Factor, 2000 (with Gayle Lynds - Covert One Series)
The Prometheus Deception, 2000 - Valonkantaja
The Janson Directive, 2000
Taken from:
http://www.kirjasto.sci.fi/ludlum.htm