Driven by an insatiable curiosity for magic, the protagonist Lucius accidentally transforms himself into a donkey, setting off a chaotic odyssey of survival. Lucius must navigate a world filled with thieves, corrupt priests, and cruel masters while trapped in his animal form. His objective is to regain his humanity, a goal that forces him to endure physical hardship and social degradation. The narrative employs a picaresque structure, moving through various episodic encounters that blend dark humor with philosophical inquiry.

Readers and critics frequently highlight the work's unique position as the only complete Latin novel surviving from antiquity. Discussion often centers on the abrupt tonal shift between the ribald, comedic early chapters and the solemn, mystical conclusion involving the goddess Isis. Scholars note the effectiveness of the world-building, which captures the anxieties and superstitions of the Roman era with remarkable clarity. The pacing is often described as brisk and episodic, allowing for a wide variety of character interactions that keep the narrative momentum high. Many readers find the blend of satire and spiritual allegory to be a complex, rewarding experience that remains relevant to modern literary study.