If I had to generalize, I'd say in clear, shallow water where the fish are heavily pressured I'd say yes, it can scare them.  But otherwise, no, not usually.  In fact, I'd say that a fighting fish can trigger a feeding "frenzy."  Many of us have observed this phenomen where you haven't gotten a bite for many minutes (or even hours) and then suddenly had the fish turn on.  I won't irrevocably state that it's always because we got the first fish to bite but I'd wager to say it is true part of the time.

In my experience a fighting fish does not scare off other fish, on the contrary, you can see other fish swarming around and follwing the fighting fish as it 's reeled in.

I think it depends on the conditions like pressured lakes and weather conditions play a hugh factor in how fish will react.  Fish can be real spooky in certain situations and alot of noise from fighting a fish in can affect the area (more so in shallow water).  But with the perfect conditions (pre fronts, current, etc;) you could drive a truck off in your favorite hot spot and still catch fish around it.  So I think it depends on the conditions you are fishing in. 

Does a fish fight scare off other fish

On the contrary, a hooked bass demonstrates hyperactive behavior

and that can only pique the curiosity of other predators. In both fresh and saltwater,

aggressive behavior is what ignites every "feeding frenzy".

In my opinion, a hooked fish is the best "fish-caller" in the world.

Particularly in spring, while leading a trophy bass to the boat,

my wife and I will often see one to three other bass of equal size,

excitedly following their tethered sister to within ten feet of our boat.

Bass know a great deal about their world, and they sense the difference between

natural and unnatural. But in my view, bass know nothing about hooks, fishing line,

boats and fishermen (lucky for us). Though you may not be aware of it,

bass often seek the shade directly beneath your boat while you're busy fishing.

I'd imagine that a hooked bass looks to another bass like a predator in hot pursuit

of some active meal, a completely natural event. Overcome by competitive instinct,

this might explain why we occasionally catch a 'doubleheader',

two bass on the same retrieve. Bass have no restaurants down there,

where they can buy food, so they instinctively know that too many missed opportunities

can cost them their lives.

Roger

I'd imagine to a bass, that another hooked bass is a predator in hot pursuit

of some active meal, which is a completely natural event.

Yup:

"Looky he got something in his mouth ! let 's go after him just in case he drops it and we get a free meal"

Thanks for all the great responses.