The story hinges on a trip to England, during which the Tsar is presented with a tiny mechanical flea. The intricate workmanship of the flea awes the Tsar, who declares that no Russian master could equal it.

Platov consistently praises Russian craftsmanship and tradition over what he experiences in Europe. This extends even to the vodka he drinks. His insistence that the masters of Tula can surpass English craftsmanship is based in part on selfish motives—he wants to go home!—and on a blind faith in the superiority of Russian virtues, including their faith.

Both Tsars in the story come off as politically naive. Tsar Alexander Pavlovich, who first encounters the mechanical flea, is shown many examples of English economic might, but the thing he fixates on is the tiny flea, for which he pays a large sum. His successor, Nikolai Pavlovich, shares Platov's belief that Russian craftsmen can surpass their English counterparts and orders that Platov take the flea to Tula. These leaders are contrasted with Lefty, who is a kind of savant, able to perform great feats of skill with no technical training.

The story satirizes Russian attitudes towards learning. Leskov does this partly through his use of made-up technical terms ("meagroscope" instead of "microscope," for instance) but also through the irrelevance of the flea itself. One of the funniest parts of the story is the decision of the Tula masters to one-up the English by fashioning tiny horse-shoes for the flea: not only are horse-shoes of any size idiotic for a flea, but their highest achievement is not the shoes but the manufacture of microscopic nails to attach the shoes to the flea. Of course, the weight of the shoes means the flea can no longer function properly when wound, so the work of Lefty and his colleagues is not only irrelevant and obscure, but also damaging.

The story is a commentary on Russian political ambitions in Europe in the 19th century. Tsar Nikolai, for example, was a reactionary who sought to crush liberalism and republicanism where he could; his decision to have the flea improved is symbolic of a larger narrow-mindedness that refused to see that change, in the form of growing mechanization and worker rights, was inevitable. Lefty, during his visit to England, is able to grasp a vital detail about cleaning guns that is far more important than all the technology of the flea, which, Leskov hints, explains Russia's defeat in the Crimean War.