Prior to that he had been in Rome, in contact with Guercino, Guido Reni and Simon Vouet. He may have had an apprenticeship with the elderly Ludovico Carracci. His initial output includes many devotional subjects. But moving to Venice under the name of Guico Baldo Canlassi da Bologna, he renewed a friendship with Nicolas Regnier, and dedicated himself to private salon paintings, often depicting sensuous naked women from thigh upwards, including Lucretia, Cleopatra, and Mary Magdalene. This allies him to a strand of courtly painting, epitomized in Florence by Francesco Furini, Simone Pignoni and others. In 1650, he moved to Venice. In 1658, he traveled to Vienna, where he remained under patronage of the emperor Leopold I.
His life was at times tempestuous, as characterized by his failed elopement (1628) with an aristocratic widow. Some contemporaries remark him as eccentric, unreliable and of doubtful morality. He is said to have enjoyed the company of cross-dressing models.
Cagnacci's work was, in one view, "entirely unappreciated by his contemporaries," but reassessed by modern critics; his painting is "warm with the heightened tones of grazing light, rich in the play of shadows and colors."
- Procession of the Holy Sacrament (Salucedio)
- Christ with Saints Joseph and Eligius (1635)
- Madonna with saints Andre Corsini Teresa and Maria Maddalena de' Pazzi (1640, Sant'Arcangelo)
- Frescoes in Cappella della Madonna del Fuoco (Duomo, Forlì)
- Allegory of spheral Astrology (Pinacoteca civica, Forlì)
- Glory of Saints Valerian and Mercurial (Faenza)
- Leopold I portrait (Vienna)
- Calling of Saint Matthew (Museo della Città - Rimini)
- Allegorical Naked Figure (private)
- The Death of Cleopatra (Pinacoteca di Brera, Milan)
- Death of Cleopatra (Kunsthistorisches Museum, Gemäldegalerie, Vienna)
- Death of Lucretia 
- Scolding of Mary Magdalene (Norton Simon Museum)
- "Guido Cagnacci". www.analesiie.unam.mx.
- Vertova, Luisa (1993). "Guido Cagnacci. Rimini". The Burlington Magazine (The Burlington Magazine Publications, Ltd.) 135 (1088: Nov.): p. 784. JSTOR 885843.
- Smyth, Francis P., and John P. O'Neill, ed. (1986). The Age of Correggio and the Carracci: Emilian Painting of the 16th and 17th Centuries. Washington: National Gallery of Art. pp. 392–397. ISBN 0-521-34019-5.
- Fossi, Gloria; Marco Bussagli and Mattia Reiche (2004). Italian Art: From the Origins to the Present Day. Catherine Frost (transl.). Florence: Giunti. p. 368. ISBN 88-09-03725-1. OCLC 44745666.
Media related to Guido Cagnacci at Wikimedia Commons