Organic farming has gained ground worldwide and has expanded in recent years due to environmental, economic, and social concerns. In Egypt, up to 1.10 % of the agricultural area is managed organically. The transition from conventional to organic farming is accompanied by changes in an array of soil properties and processes that affect soil fertility. These changes in soil properties under Egyptian condition are not well documented. Therefore, the present study was carried out to study the comparative effects of organic and conventional farming systems on some soil chemical and biological indicators under Egyptian conditions. Surface soil samples (0-30 cm) were collected from eight field pairs (one organic field ant its conventional counterpart) to represent three organic farms in three governorates. Three organic fields which were in organic practice for four; six, and ten years since certification and three adjacent conventional fields were chosen from Fayoum Organic Farm, Tubhar city, Fayoum Governorate. Two organic fields which were in organic practice for twenty and thirty years since certification and two adjacent conventional fields were chosen from SEKEM Organic Farm, Bilbeis city, Sharkyia Governorate. Three organic fields which were in organic practice for eight, ten and twelve years since certification and three adjacent conventional fields were chosen from a private organic farm located in Salhyia city, Ismailia Governorate. The studied soil chemical indicators include soil organic carbon, T-N, pH, EC, Ex-Cations, and Available N, P, K, Fe, Mn, Zn, Cu while the biological indicators include population of bacteria, actinomycetes, azotobacter and fungi as well as dehydrogenase, alkaline phosphatase and Urease activities. Organically managed soils showed significantly better soil nutritional and microbiological conditions regardless of periods of organic farming practice. Soil organic carbon, T-N, and available N, P, K, Fe, and Mn contents were significantly higher in the organic system than in the conventional system. Soil pH, EC, available Cu and Zn were higher in the conventional system than in the organic system. The microbial communities (bacteria, actinomycetes, azotobacter & fungi) and enzyme activities (dehydrogenase, alkaline phosphataes & urease) were also greater in soils from organic system.