Heart of Darkness is the quintessential colonial tale: it's about a guy who works for a Belgian ivory-trading company and sails along the Congo River witnessing the hatred, violence, and misunderstanding between the greedy colonizers and the "'savage"' natives—some of whom have imprisoned one of the other ivory guys so they can worship him as a god. Offended yet?
Let's be clear. How do postcolonial theorists feel about this classic novella from a Polish author writing in English? In a word (or two): hate it.
Sure, there might be some postcolonial readings that "'complicate"' the text more, but—for the most part—poco theorists have mad respect for the first (and final) poco reading on HOD: Chinua Achebe's essay "'An Image of Africa: Racism in Conrad's Heart of Darkness."'
So what does Achebe say? Basically, that HOD and Conrad are—as you might guess from the essay title—racist. How so? Even though the bulk of the story takes place in the Congo, no one from the Congo actually gets a real speaking part or features as anything but some thing weird, fearsome, and—for lack of a better word—"'Other."'
The Congo doesn't fare much better: it's a dark, dark place that induces insanity in our European "'hero."' And even though the book can always be read as anti-colonialist, the story doesn't really feel like it's against colonialism for the right reasons—that is, if you're thinking like Achebe.