This has cropped up a few times, and I myself started a thread about this sometime last week about the apparent disparity between the number of corpses lying about and the number of homes we see in and about Tristram.

But seriously, how many dead villagers are there really? What idiot would take the time to actually count them? Well, you need look no further to find your idiot; I am that idiot.
Your mileage may vary, but I came up with a total of 354

For the record, I counted them by zone, and I only counted dead villagers that I could search, or villagers that were about to die (such as the dying villagers in the Slaughtered Calf Inn or the Cellar of the Damned). I didn’t bother counting corpses lying about for decoration.

If you’re wondering about the breakout (and even if you’re not):

Adira’s Hut: 5
Old Tristram Road: 7
Tristram: 5
Cathedral Level 1: 26
Cellar of the Damned: 15
Slaughtered Calf Inn: 7
Khazrah Den: 5
Weeing Hollow: 13
Cemetery of the Forsaken: 1
Cathedral Level 2: 29
Cathedral Level 3: 15
Cathedral Level 4: 19
Royal Crypt: 7
Fields of Misery: 18
Scavenger s Den Level 1: 17
Scavengers Den Level 2: 9
Wortham Village/Cliffs: 18
Highland Crag: 3
Southern Highlands: 9
Watchtower Level 1: 22
Watchtower Level 2: 9
Cave of the Moon Clan Level 1: 18
Cave of the Moon Clan Level 2: 12
Northern Highlands: 11
Leorics Hunting Ground: 8
Leorics Manor Courtyard: 9
Leorics Manor: 4
Halls of Agony Level 1: 9
Halls of Agony Level 2: 17
Halls of Agony Level 3: 10
Highland Passage: 2

Yes, I do have too much time on my hands as a matter of fact.