Here is the full list of all 57 Star Wars Knights of the Old Republic II: The Sith Lords achievements.
Acquire all Light Side Powers
Teach the Handmaiden the ways of the Force.
Listen to HK-47's definition of love.
Have your character replace any of the Sith Lords on the main menu screen.
Claim Darth Nihilus' mask.
Reach Player Level 30
Acquire all Dark Side Powers.
Kill all the Jedi masters
Have 30 points in Demolitions.
Get this by starting the "Trapped" Quest on Korriban.
Deduce G0-T0's identity
Learn how to kill Jedi from HK-47
Convince Vogga the Hutt to sell fuel to Telos.
Have 30 points in Treat Injury.
Have 30 points in Stealth
Have 30 points in Repair.
Have 30 points in Computer Use.
Convince the "champ" to lose the game without playing.
Reduce a companion's Influence to zero.
Dance for Vogga
Complete the game on the Light Side
Install HK-47's unique module
Side with the Queen on Onderon
Complete the Mandalorian Battle Circle
Learn Moving Meditation
Side with the Settlers at Khoonda
Change your mind about siding with the Settlers at Khoonda
Recruit the Disciple
Get the named Lightsaber crystal
Recruit Mira
Complete the Handmaiden Battle Circle
Reach maximum Light Side points
Let the Sith destroy the Peragus Asteroids
Get your first Light Side points
Complete the game on the Dark Side
Have Persuasion over 30
Defeat Sion
Defeat Nihilus
Side with Vaklu on Onderon
Flee Korriban after fighting Sion
Fill the Party Selection screen
Loot a body on Korriban
Gain a Prestige class
Break Hanharr's spirit
Beat the champ on Nar Shadaa
Repair the damaged droid on the Ebon Hawk
Contruct your first Lightsaber
Recruit Hanharr
Reach maximum Dark Side points
Learn Force Sight
Collect 10,000 credits
Recruit the Handmaiden
Win a Pazaak game with a full board
Destroy Peragus Astroids
Kill all Sith troopers before they can board the Ebon Hawk
Get your first Dark Side points
Complete the Prologue