36 zips
| Zip Code | City | Population ↓ |
|---|---|---|
| 08854 | Piscataway | 60,405 |
| 08861 | Perth Amboy | 58,264 |
| 08901 | New Brunswick | 56,766 |
| 08831 | Monroe Township | 54,608 |
| 08816 | East Brunswick | 48,965 |
| 08817 | Edison | 47,924 |
| 08902 | North Brunswick | 43,146 |
| 08857 | Old Bridge | 40,409 |
| 08820 | Edison | 39,392 |
| 07747 | Matawan | 32,246 |
| 07008 | Carteret | 25,220 |
| 08859 | Parlin | 24,284 |
| 07080 | South Plainfield | 24,215 |
| 08879 | South Amboy | 23,263 |
| 08536 | Plainsboro | 20,558 |
| 07095 | Woodbridge | 20,086 |
| 08872 | Sayreville | 20,040 |
| 08837 | Edison | 19,954 |
| 08830 | Iselin | 19,151 |
| 07067 | Colonia | 18,294 |
| 08840 | Metuchen | 17,934 |
| 08852 | Monmouth Junction | 17,333 |
| 07001 | Avenel | 17,143 |
| 08882 | South River | 16,007 |
| 08904 | Highland Park | 14,981 |
| 08846 | Middlesex | 14,518 |
| 08824 | Kendall Park | 13,866 |
| 08863 | Fords | 13,052 |
| 08512 | Cranbury | 12,511 |
| 08850 | Milltown | 8,442 |
| 08810 | Dayton | 8,241 |
| 08884 | Spotswood | 8,133 |
| 07064 | Port Reading | 3,742 |
| 07077 | Sewaren | 3,196 |
| 08832 | Keasbey | 2,793 |
| 08828 | Helmetta | 2,317 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 36 ZCTAs in Middlesex County, New Jersey (US Census).