FROM 1947 TO 1971 DIETHYLSTILBESTROL (DES) WAS COMMONLY PRESCRIBED FOR USE BY PREGNANT WOMEN TO PREVENT MISCARRIAGES. THE DRUG LATER WAS LINKED TO SUBSEQUENT DEVELOPMENT OF CANCER AND PRECANCEROUS CONDITIONS IN SOME DAUGHTERS EXPOSED TO THE DRUG IN UTERO. SEVERAL HUNDRED OF THESE DAUGHTERS ARE PLAINTIFFS IN AN ESTIMATED 80 TO 100 CASES PENDING IN THE UNITED STATES. MOST OF THE MAJOR DRUG COMPANIES ARE DEFENDANTS. THE PLAINTIFFS FACE A NUMBER OF LEGAL PROBLEMS, UNIQUE AMONG WHICH IS THE ISSUE OF CAUSE-IN-FACT. BECAUSE OF THE TIME LAPSE INVOLVED, MOST PLAINTIFFS CANNOT IDENTIFY THE MANUFACTURER OF THE DRUG TAKEN BY THEIR MOTHERS. IN SUCH CASES, PLAINTIFFS HAVE JOINED AS MANY AS 94 DES MANUFACTURERS AS DEFENDANTS, ALLEGING JOINT AND SEVERAL LIABILITIES. UNDER EXISTING LAW TWO POSSIBLE THEORIES -- CONCERTED ACTION AND ALTERNATIVE LIABILITY -- COULD BE USED BY PLAINTIFFS IN THESE CASES. NEITHER THEORY HAS BEEN APPLIED TO A FACTUAL PATTERN AS COMPLEX AS THAT INVOLVED IN THE DES CASES. ANALYSIS OF THE LOGIC, POLICY, AND PRACTICE OF EACH THEORY RELATIVE TO DES CASES INDICATES THAT JOINT AND SEVERAL LIABILITY MIGHT BE FOUND UNDER EITHER THEORY BUT THAT A THIRD THEORY -- ENTERPRISE LIABILITY -- MAY BE A BETTER SOLUTION TO THE CAUSATION PROBLEMS. ENTERPRISE LIABILITY, A FUSION OF ALTERNATIVE AND CONCERT THEORIES, REQUIRES THE PLAINTIFF TO PROVE A HIGH PROBABILITY THAT HER INJURY WAS CAUSED BY THE TORTIOUS BEHAVIOR OF ONE OF THE DEFENDANTS AND THAT THE DEFENDANTS CONCERTEDLY ADHERED TO A DANGEROUS, INDUSTRYWIDE SAFETY STANDARD IN THEIR MANUFACTURE OF THE INJURY-PRODUCING PRODUCT. EVIDENCE OF THESE TWO ELEMENTS SHIFTS THE BURDEN OF PROOF ON CAUSATION TO THE DEFENDANTS. OTHER APPLICANTS OF ENTERPRISE LIABILITY THEORY ARE NOTED. NOTES ARE INCLUDED. (AUTHOR ABSTRACT MODIFIED--LKM)