While out on a date – a young; confident; and carefree girl comes across the most addictive of aromas. She follows it like a drug only to be lead to a dead body. Now her morals are at war with her new found obsession – She’s addicted to the smell of death.

I'm hooked but the "while on a date" part leaves me questioning why is it important to mention, you know? Was it something that happened there? Did it involved her date?

Jim isn't your version like a teaser? just the last part of it because your stating a question the log line is meant to tell the whole in a few lines not leave us with guesses.

VERY NICE! Agree with Alice ... great hook ... and creepy! haha

But in terms of formatting loglines, we'll need to clean this up and make it more concise while identifying the protag, antag, the world around us, and the time restriction (if possible).

How about this (at least for a starting point):

"When a young and carefree girl is drawn to the sweetest of aromas, she's discovers the source: a decaying body. Can she control her addiction for the stench of death or will she hunt for more in the urban jungle?"

(I've taken the liberty to assume she lives in or near a "big city".)

Love how dark it is. I'm hooked - but I want to know more about what her strange new obsession will drive her to do. Will she start roaming the dangerous parts of the city at night, hunting for corpses? Is she tempted to become violent? Will she go to TAFE and study to be a professional embalmer? In terms of logline structure, feel like you need to distil it to be more succinct, and tighten the formatting. The first dash doesn't need to be there, and you should be using commas instead of semicolons.