| Index | Islip | New York | National |
| Average Test Scores | 54% | 56% | 48% |
| Student/Teacher ratio | n/a | n/a | 16:1 |
| Total public schools | 5 | 4,060 | 79,221 |
| Total private schools | n/a | 1,092 | 24,874 |
| Total post-secondary schools | n/a | 483 | 7,963 |

| Index | Islip | New York | National |
| Completed 8th grade | 89.9% | 83.5% | 84.3% |
| Completed high school | 89.1% | 82.1% | 83.0% |
| Completed some college | 61.5% | 59.5% | 59.4% |
| Completed associate degree | 41.5% | 43.4% | 38.5% |
| Completed bachelors | 33.7% | 34.7% | 30.3% |
| Completed masters | 13.7% | 15.1% | 11.5% |
| Completed professional degree | 2.0% | 4.2% | 3.3% |
| Completed doctorate | 0.1% | 1.5% | 1.3% |
There are a total of 5 public schools, n/a private schools and n/a post-secondary schools in Islip. Using the proficiency score averages, the average test scores for Islip, NY schools is 54%. The average student to teacher ratio is n/a. In Islip, NY, an average of 89.9% of students have completed 8th grade and an average of 89.1% have completed high school.
| City | Population | Avg. Test Scores | National Avg. |
| Old Bethpage, NY | 5,640 | 90% | 86.5% |
| Cold Spring Harbor, NY | 2,967 | 87% | 81.3% |
| Plainview, NY | 26,865 | 83% | 72.1% |
| Syosset, NY | 19,723 | 83% | 71.9% |
| West Sayville, NY | 5,133 | 82% | 69.8% |
| Islip, NY | 17,559 | 54% | 13.0% |
| City | Population | Avg. Test Scores | National Avg. |
| East Cleveland, OH | 17,563 | 24% | 49.8% |
| Wayne, MI | 17,566 | 19% | 60.1% |
| Poplar Bluff, MO | 17,570 | 56% | 16.3% |
| Springfield, TN | 17,576 | 28% | 42.2% |
| Massapequa Park, NY | 17,537 | 64% | 32.6% |
| Islip, NY | 17,559 | 54% | 13.0% |