Nigro has listed some of his major dramatic influences as Shakespeare and the Jacobeans, Samuel Beckett, Harold Pinter, Peter Barnes, Tom Stoppard, and the early work of John Arden and Edward Bond.
[8] His long cycle of Pendragon County plays, now numbering well over two dozen and still growing, traces American history from the eighteenth century to the present through the lives of several generations of interconnected families from an east Ohio town.
These include Glamorgan, Horrid Massacre In Boston, Armitage, Fisher King, Green Man, Sorceress, Tristan, Pendragon, Chronicles, Anima Mundi, Beast With Two Backs, Laestrygonians, The Circus Animals' Desertion, Dramatis Personae, The Reeves Tale and November.
Other plays include Machiavelli, Ardy Fafirsin, A Lecture By Monsieur Artaud (about Antonin Artaud), Grotesque Lovesongs (originally commissioned by producer Saint Subber), Mariner (about Christopher Columbus), Jules Verne Eats A Rhinoceros (about reporter Nellie Bly), Punch and Judy, Boar's Head (about the lives of the supporting characters at the Boar's Head Inn in Shakespeare's mentioned but unwritten scenes from his Henry IV plays), Loves Labours Wonne (about Shakespeare), Paganini, Lucia Mad (about the daughter of James Joyce), Cinderella Waltz, Specter, Monkey Soup, Don Giovanni, The Count of Monte Cristo In The Chateau D'If, Quint And Miss Jessel At Bly, The Girlhood Of Shakespeare's Heroines, Terre Haute, The Transylvanian Clockworks, Seascape With Sharks and Dancer, Henry And Ellen (about Henry Irving and Ellen Terry), The Dark Sonnets Of The Lady (about Sigmund Freud and his patient Dora), Seduction (inspired by Søren Kierkegaard's Diary of a Seducer), Rainy Night At Lindy's (about the last night of gangster Arnold Rothstein), What Shall I Do For Pretty Girls?
In 2024 three of his plays, Ravenscroft, Maddalena and Animal Tales, were being performed by the repertory company at the Chekhov Theatre in Chisinau, Moldova, in the translations of Victor Weber, directed by Iosif Shats.
[14] The Jerome Lawrence and Robert E. Lee Theatre Research Institute at the Ohio State University in Columbus has archived a large collection of Nigro's scripts and related materials.