The 120 members of the first Knesset were elected on 25 January 1949. The breakdown by party was as follows:
46
19 (gained one member during the Knesset term)
16
14 (lost two members during the Knesset term)
7
5
4
4 (lost one member during the Knesset term)
2
1
1
1
| MK | Replaced | Party | Date | |
|---|---|---|---|---|
| Eliyahu Mazur | Moshe Kelmer | United Religious Front | 11 March 1949 | |
| Yitzhak Kanav | Avraham Taviv | Mapai | 20 April 1950 | |
| Herzl Berger | Yehudit Simhonit | Mapai | 5 February 1951 | |
| Jenia Tversky | Heshel Frumkin | Mapai | 5 February 1951 | |
| Yisrael Yeshayahu | Aryeh Sheftel | Mapai | 12 February 1951 | |
| Baruch Osnia | Abba Hushi | Mapai | 12 February 1951 | |
| Menachem Ratzon | Dov Bar-Nir | Mapam | 10 April 1951 | |
| David Livschitz | Yitzhak Tabenkin | Mapam | 12 April 1951 | |
| Menachem Cohen | David Remez | Mapai | 19 May 1951 | |
| Rafael Bash | Yosef-Michael Lamm | Mapai | 21 May 1951 |