| Index | Portsmouth | Iowa | National |
| Average Test Scores | n/a | 69% | 48% |
| Student/Teacher ratio | n/a | 13:1 | 16:1 |
| Total public schools | n/a | 1,101 | 79,221 |
| Total private schools | n/a | 208 | 24,874 |
| Total post-secondary schools | n/a | 96 | 7,963 |

| Index | Portsmouth | Iowa | National |
| Completed 8th grade | 85.6% | 89.2% | 84.3% |
| Completed high school | 82.2% | 87.7% | 83.0% |
| Completed some college | 40.7% | 59.8% | 59.4% |
| Completed associate degree | 22.0% | 38.4% | 38.5% |
| Completed bachelors | 7.6% | 27.2% | 30.3% |
| Completed masters | 0.8% | 8.7% | 11.5% |
| Completed professional degree | 0.0% | 2.7% | 3.3% |
| Completed doctorate | 0.0% | 1.1% | 1.3% |
There are a total of n/a public schools, n/a private schools and n/a post-secondary schools in Portsmouth. Using the proficiency score averages, the average test scores for Portsmouth, IA schools is n/a. The average student to teacher ratio is n/a. In Portsmouth, IA, an average of 85.6% of students have completed 8th grade and an average of 82.2% have completed high school.
| City | Population | Avg. Test Scores | National Avg. |
| Logan, IA | 1,591 | 81% | 69.3% |
| Harlan, IA | 4,917 | 81% | 68.1% |
| Woodbine, IA | 1,419 | 78% | 63.0% |
| Avoca, IA | 1,413 | 77% | 61.1% |
| Dunlap, IA | 1,246 | 70% | 44.8% |
| Portsmouth, IA | 174 | n/a |
| City | Population | Avg. Test Scores | National Avg. |
| Pickering, MO | 174 | 55% | 14.6% |
| Reeves, LA | 174 | 77% | 60.4% |
| Concord, AR | 174 | 46% | 4.7% |
| Burlington, OK | 174 | 50% | 4.2% |
| Monroe, OK | 174 | 25% | 47.9% |
| Portsmouth, IA | 174 | n/a |