We have developed sensitive assays for viremia and cell-associated human immunodeficiency virus type 1 (HIV-1) RNA and DNA to assess the predictive value of virological parameters determined in blood for virus load in lymph nodes (LNs). Eighteen patients were included; 13 received stavudine/didanosine/hydroxyurea and 5 stavudine/didanosine, and all had viremia <500 copies/mL for >3 months. At the time of LN biopsy (median, 10 months), the median viremia was 2.09 log copies/mL (range, <0.70–3.34). Cell-associated HIV-1 RNA and DNA were detectable in blood and LNs of all patients. The median cell-associated RNA and DNA were 2.16 log copies/10⁶ cells and 2.60 log copies/10⁶ cells in blood versus 4.31 log RNA copies/10⁶ cells and 3.26 log DNA copies/10⁶ cells in LNs. Regression analysis shows that, in treated patients with sustained low viremia, cell-associated RNA and DNA in blood are better predictors of virus load in LNs than viremia.