Before (end of 1983) (33 seats, Elections Centre)
Labour 32 · Other 1 · Plaid Cymru - The Party of Wales 0 · SDP-Liberal Alliance 0 · Conservative 0
After (end of 1984) (33 seats, Elections Centre)
Labour 30 · Other 3 · SDP-Liberal Alliance 0 · Conservative 0 · Plaid Cymru - The Party of Wales 0
Ward results
Dowlais2 seats
| E. Thomas | Independent | 980 |
| D. Lewis | Labour | 892 |
| W. Healy | Independent | 887 |
| M. Sullivan | Ind Lab | 764 |
| C. Parker | Labour | 762 |
Penydarren1 seat
| D. James | RATE | 1,046 |
| M. Keane | Labour | 751 |
| A. Jones | COMM | 200 |
Plymouth Ward1 seat · turnout 42.7%
| M. Tasker | Labour | 1,136 |
| C. Foley | Plaid Cymru - The Party of Wales | 584 |
Treharris1 seat
| M. Shankland | Labour | 961 |
| E. Galsworthy | COMM | 764 |