The East Zone of the Ranji Trophy, 1984-85 saw the participation of all the 4 regular teams, including the likes of Bengal, Bihar, Assam and Orissa. The teams were hailing from the Eastern region of India and they had been playing in the tournament on a regular in the previous several editions. The teams played against each other in the zonal level league matches with a view to become one of the top two teams in the zone. Securing a birth in the knock out level of the tournament was also another principal aim of the teams, however, only the teams like Orissa and Bihar could achieve the aim. The Orissa and Bihar teams earned total 46 and 44 points, respectively, at the end of the zonal level league matches.

The Assam and Bengal teams played against each other in the first of the East Zone league matches in the Ranji Trophy, 1984-85 and the match was held at Nowgong from 24-26 November, 1984. The drawn match saw the Bengal and Assam teams earning 6 and 4 points, respectively from it. The Bihar team played against the Orissa team in the second match of the East Zone and the two teams played the match at Ranchi from 24-26 November, 1984. The match remained drawn during the specified period of time and the match officials awarded both the Bihar and Orissa teams 9 points, each for the match.

The teams of Bengal and Bihar clashed with each other in the third of the East Zone league matches in the Ranji Trophy, 1984-85 and the match was held at Calcutta from 01-03 December, 1984. The drawn match saw the Bengal team earning 11 points and Bihar earning 9 points from it. The next match of the zone involved the teams like Assam and Orissa and the two teams played the match at Nowgong from 01-03 December, 1984. The Orissa team played wonderfully in the match and earned 31 points from it, by clinching a victory of an innings and 115 runs. The Assam team earned 3 points from the match, as well.

The Assam team appeared in the next match of the East Zone also and this time, it played against the Bihar team at Nowgong from 06-08 December, 1984. The Bihar team showed a very good performance in the match and clinched a huge victory of 81 runs for earning 28 points from it. The match also saw the Assam team earning 7 points. The last of the East Zone league matches in the Ranji Trophy, 1984-85 saw a clash between the teams of Bengal and Orissa and the match took place at Calcutta from 08-10 December, 1984. The match remained drawn during the stipulated duration and both the Orissa and Bengal teams earned 8 points, each from the match.