My neighbour gave me $150 as a gift and now after an unrelated disagreement he wants it back. Will I have to pay him back if he takes me to small claims court?

It was a gift. Unless there was a written legal contract signed by both of you, or a verbal contract, i.e. one where you both agreed that you pay them back; there is no legal obligation to pay them back. :) x

Most likely not but we do not have every bit of info. Questions like; can he prove it was even handed to you; can you prove it was a gift and not a loan, etc... He sauid she said it court usually goes nowhere so I think you are OK.

This is what happens, esp if this is small claims court,

You will tell your side of the story, he will tell his side. If there is any evidence or witnesses they will be called and that evidence shown.

The judge then decides on who he believes the most.
If your neighbor says you promised to pay him back, you say it was a gift, often the story you say or info you give makes the judge believe on over the other.

So there is not even a good guess at what a local small claims judge may decide.

A gift does not normally have to be repaid, but proving it was a gift?