- Poffenberger, Albert T. (Albert Theodore), 1885-1977, author1
- Pool, Eugene H. (Eugene Hillhouse), 1874-1949, author1
- Pope, Amy Elizabeth, 1869- author1
- Porter, Charles Sanford, 1862- author1
- Porteus, S. D. (Stanley David), 1883-1972, author1
- Pou Orfila, Juan.1
- Prat, Domingo, 1882- author1
- Prinz, Hermann, 1868-1957, author1
- Prothero, James Harrison, author1
- Prunell, A. (Alfredo), author1
- Pyle, William Henry, 1875- author1
- Raiziss, George W., 1884- author1
- Ramon y Cajal, Santiago, 1852-1934, Author3
- Ramon y Cajal, Santiago, 1852-1934, author1
- Ramsey, Walter Reeve, 1872- author1
- Ratcliff, A. J. J. (Arthur James John), 1894- author1
- Read, Lillian, A., author1
- Reed, Charles B. (Charles Bert), 1866- author1
- Reid, E. Priscilla (Elizabeth Priscilla), author1
- Reid, William Duncan, 1885- author1