Over the past few decades, “chaos theory” and “complexity theory” have emerged as new scientific models for understanding chaotic and/or complex systems. Chaos theory has grown out of physics and mathematics. Complexity theory has developed mainly from studying biological and human systems. These theories share a natural alignment with the spirit and practice of astrology, more so than other attempts to use astrology with the concepts of modern science. The current configuration of Uranus and Pluto makes this an auspicious time to discuss chaos and complexity theory with astrologers.