There are 51 Trophies that can be collected.

BRONZE

Thief
You pickpocketed items worth a total of 200 coins

Versatile
You killed characters with each weapon and offensive gadget

Wall of Sparks
You killed an enemy with the Wall of Light

Rogue
You assassinated 10 unaware enemies

Specter
After escaping prison, you completed a mission, not alerting anyone and killing less than 5 people

Faceless
After escaping Coldridge Prison, you completed a mission without alerting anyone

Manipulator
You made others kill 5 of their own allies

Razor Rain
You killed 5 characters with Drop Assassination

Harm's Way
You caused 5 unintentional suicides

Inhabitant
You stayed in possession of others for most of a 3 minute period

Hornets' Nest
You killed 4 enemies in less than 1 second using the crossbow

Speed of Darkness
You travelled 30 meters in less than 1 second

Tempest
You killed 6 enemies in less than 1 second

Merchant of Disorder
You acquired 15 equipment upgrades

Occultist
You collected 10 bone charms

The Escapist
After Coldridge Prison, you eluded 5 pursuers at once without killing them or leaving the map

Cleaner
You fought 5 enemies at once and none of them survived

Dishonored
You escaped Coldridge Prison

Excommunication
You eliminated High Overseer Campbell

Child Care
You located Lady Emily Kaldwin, heir to the throne

Capturing Genius and Madness
You abducted Anton Sokolov, Royal Physician

Regicide
You assassinated the Lord Regent, Hiram Burrows

Political Suicide
You brought about the Lord Regent's fall from grace by broadcasting his crimes

This is Mine
You recovered your belongings

Back Home
You grabbed a live grenade and threw it back, killing an attacker

Big Boy
You killed a tallboy using only your sword

SILVER

Ghost
You completed all missions after the prologue, alerting or killing no one but key targets

Shadow
You completed all missions after the prologue without alerting anyone

Mostly Flesh and Steel
You finished the game without purchasing any supernatural powers or enhancements, besides Blink

Surgical
You played from the first mission through Kaldwin's Bridge killing fewer than 10 characters

Art Dealer
You collected all the Sokolov paintings

GOLD

Clean Hands
You completed the game without killing anyone

Resolution
You completed the game

PLATINUM

Platinum Blades and Dark Corners
You have mastered the City of Dunwall and unlocked all Trophies

17 SECRET

http://www.ps3trophies.org/game/dishonored/trophies/