According to the 1978 population census, Ochamchira had 18,700 residents. After the Georgian-Abkhaz conflict of 1992-93, Ochamchira experienced a significant population decline due to ethnic cleansing of Georgians. Most of the internally displaced persons who were affected by the conflict have yet to return to the city. Ochamchira lies along the left bank of the Ghalidzga (Aaldzga) River at an elevation of 5 metres (16 feet) above sea level. The city is located 53 kilometres (33 miles) southeast of Sukhum capital city. Ochamchira's climate is humid subtropical, with mild winters and hot summers. The average annual temperature is 13.6 degrees Celsius. January's average temperature is 4.5 degrees Celsius while the average temperature in July is 23 degrees Celsius. Average annual precipitation is approximately 1,300 mm (51 in).
Ochamchire evolved as a town from a small maritime settlement, which was a scene of fighting between the Russians and Turkish-Abkhaz forces in 1877.
The ancient Greek colony of Gyenos (Greek: Γυένος) is supposed to have located near Ochamchira, though the identification cannot be considered as definitive because of doubts as to the actual location and the very poor preservation of the archaeologic site itself.