Polymerase chain reaction is commonly used to detect t(11;14)(q13;q32) and t(14;18)(q32;q21) chromosomal translocations associated with mantle cell lymphoma and follicular lymphoma. We tested a total of 482 samples from patients with suspected non-Hodgkin's lymphoma and sequenced unusual-sized t(11;14)(q13;q32) and t(14;18)(q32;q21) products from 33 of these patients. BCL-1 or BCL-2 gene rearrangements were confirmed in 23 of 33 patients (70%). Considerable size variation was observed using t(11;14) primers, with MTCA and MTCB t(11;14) products ranging from 234 to 934 bp and 143 to 560 bp respectively. Less variability was observed for t(14;18) Major Breakpoint Region (MBR) products (100-252 bp) but Minor Cluster Region (MCR) products ranged from 217 to 498 bp. We demonstrate the utility of sequence analysis to confirm unusual-sized translocation products and reduce false-positive results because of nonspecific amplification.