- City Investing Co.5
- Clark T. Chambers, Inc.1
- Clayton Apartments, Inc.12
- Clement E. Merowit and Co.1
- Clinton Housing Association1
- Cloverton Corp.3
- Clyde Management Corp.1
- Coates Realty Corp.4
- Cohen Brothers Realty16
- Cohen Brothers Realty and Construction Corp.18
- Coldwell Banker1
- Collins, Tuttle and Co.25
- Conforti, James, Jr.2
- Convent Gardens, Inc.1
- Cooper-Bregstein Realty Co.18
- Corcorar, Francis2
- Cord-Meyer Development Co.1
- Corey, Russel B.1
- Cosmopolitan Associates1
- Cowan, Louis2
- Crandall, Edward H.1
- Cross Properties, Inc.26
- Cross and Brown Co.68
- Cruikshank Co.26
- Culver Associates, Inc.8
- Culver, Hollyday and Co., Inc.22
- Cushman and Wakefield, Inc.103
- D.S. 90th Street Associates1
- D.S. Wasserman Associates1
- DBF Construction Corp.1
- DBS Associates5
- Dahage Realty Corp.11
- David W. Frankel2
- Day, Harry A.1
- Decatur Estates1
- Delagart Realty Corp.3
- Delgais Realty, Inc.1
- Denberg, Louis2
- Denihon, B.J.14
- Diamond, Arthur6
- Diamond, Sidney6
- Diesel Construction Co., Inc.1
- Diesel Electric Co., Inc.3
- Digby Management Co.2
- Dilliard Corp.1
- Distillator, Abner1
- Donald W. Brown, Inc.7
- Donohue Co. Real Estate, Inc.1
- Dorothy Somekh Realty1
- Douglas Elliman-Gibbons and Ives, Inc.13
- Douglas Gibbons and Co., Inc.13
- Douglas Gibbons-Hollyday and Ives, Inc.82
- Douglas L. Elliman & Co., Inc.1
- Douglas L. Elliman and Co., Inc.436
- Douglas Robinson, Charles S. Brown Co.1
- Douglas, Gibbons and Co., Inc.3
- Douglass, Lathrop3
- Downe, H. Russell, Jr.2
- Duell, Manny E.1
- Duff V. Conger, Inc.4