Who is responsible for cleaning at the end of a lease?

[Lyle Cooper]

The tenant or the landlord?  Location is NYC.

[Nathan Gesner]

The tenant is required to return the property "in the same or better condition" as it was received. If you gave it to them dirty, they can return it dirty.

My policy is to clean the rental as well as I can. The cleaner it is when they move in, the easier it is to hold them accountable for cleaning when they leave. The dirtier it is, the less likely you are to get a quality tenant and the more likely they are to neglect the home. 

If the floors were clean when the tenant moved in, they should clean them when they move out. If they don't, you charge them for it. I personally take hundreds of pictures to document the condition the rental before the tenant moves in. I take pictures of front/back of doors, inside/outside of appliances, window treatments open/closed, floors, ceilings, every wall, window tracks, screens, fixtures, under the sinks, inside cabinets and drawers, etc.

The better you document the condition prior to move-in, the easier it is to hold them accountable when they move out.