The first episode of the new psychological thriller aired at 9pm last night (Monday) after much hype from the critics.
And according to overnight figures, 3.53 million tuned in to its BBC 2 debut.
The ratings are expected to rise further once iPlayer views are taken into account.
The five-parter stars X Files actress Gillian Anderson and Co Down actor Jamie Dornan.
Anderson plays DSI Stella Gibson, an officer drafted in by the PSNI to help solve a grisly murder, while Dornan takes on the role of serial killer Paul Spector, who terrorises the women of Belfast.
Critics have compared the drama to Scandinavian hits like The Killing. The Guardian said: "Move over Denmark, Belfast is the new Copenhagen? Could be."
COMMENT RULES: Comments that are judged to be defamatory, abusive or in bad taste are not acceptable and contributors who consistently fall below certain criteria will be permanently blacklisted. The moderator will not enter into debate with individual contributors and the moderator’s decision is final. It is Belfast Telegraph policy to close comments on court cases, tribunals and active legal investigations. We may also close comments on articles which are being targeted for abuse. Problems with commenting? firstname.lastname@example.org
Getting advanced training will open doors for you. If you get a chance to study overseas, grab it. Learning a foreign language will make you indispensible to the job market. It will also allow you to travel the world. You've always been restless and adventuresome. Being able to experience different ways of life will fill you with happiness. Although you will miss loved ones while you're away, you'll make friends wherever you go. That's what comes of being so popular.More