A wide variety of techniques have been explored to synthesize small diameter tissue engineered blood vessels. Cell sheets rolled around a tubular mandrel to mimic native blood vessel have shown mechanical properties and functional characteristics similar to the native blood vessels, and provide evidence that cells are able to produce their own matrix and remodel into a tissue. However, the entire process takes approximately 3 months. Alternatively, we and others are exploring direct cell seeding and growth on tubular mandrels as a means of forming vascular tissues in a shorter time period. In the present study, v-shaped chambers cast from agarose were used as cell seeding wells. Fibrin microthreads placed in the chamber were used as tubular seeding mandrels. Human mesenchymal stem cells (hMSCs) were seeded for 4 hours, which resulted in uniform attachment onto the microthreads. Cell attachment to the microthreads was confirmed visually by Hoechst nuclear staining. A cell quantification assay showed that 1654plusmn22 cells attached per 1 cm fibrin microthread sample (n=3). These results indicate that hMSCs adhere rapidly to fibrin microthreads, and will form the basis for future studies aimed at optimizing cell attachment for cellular microvessel generation.