After the sudden death of his father leaves his family destitute, young Nicholas Nickleby must navigate a predatory society while attempting to protect his mother and sister from his callous uncle. Nicholas seeks employment and stability, yet he is repeatedly thwarted by the machinations of Ralph Nickleby, a man whose greed dictates his treatment of his kin. The narrative follows Nicholas as he encounters a diverse array of characters, ranging from the abusive staff of Dotheboys Hall to a traveling theatrical troupe. Written in a third-person omniscient perspective, the novel tracks the protagonist's moral development as he confronts systemic cruelty and personal betrayal.

Readers and critics frequently highlight the novel's balance between biting social commentary and Dickens's signature comic flair. Discussion often centers on the vividness of the secondary characters, who are often cited as some of the most memorable figures in the author's bibliography. Many observers note the effectiveness of the Dotheboys Hall chapters in exposing the harsh realities of nineteenth-century schooling. The pacing is often described as energetic, reflecting the serial nature of its original release. Scholars frequently emphasize how the work serves as a pivotal example of the author's ability to blend moral outrage with high-spirited entertainment.