I Didn't Know What to Do by Gilbert O'Sullivan first appeared on the Israeli foreign-music chart on 19 Sep 1971, entering at #18. It peaked at #17 on 26 Sep 1971. In total it spent 2 weeks on the chart, last charting on 26 Sep 1971.
| Wk | Date | Pos |
|---|---|---|
| 1 | 19 Sep 1971 | 18 |
| 2 | 26 Sep 1971 | 17 |