Static light-scattering behavior was investigated for semidilute n-hexane Solutions of poly-(n-hexyl isocyanate) (PHIC). At 25 degreesC, the monomer-unit structure factor (S) over cap (k) of the solutions was favorably compared with the generalized Ornstein-Zernike integral equation theory, and the strength of the attractive interaction between PHIC chains in n-hexane was estimated to be very weak, On the other hand, after the solutions were quenched at 15 degreesC, theoretically unexpected enhanced low-angle scattering was observed. While (S) over cap (k) gradually increased with the quenching time, the anomaly disappeared by heating or diluting the solutions. The normal (S) over cap (k) was also recovered by subtracting the anomalous, component from (S) over cap (k) of quenched solutions using dynamic light-scattering results. The anomaly in (S) over cap (k) indicates the formation of aggregates or clusters of PHIC chains in quenched solutions. A strong interchain attractive interaction expected in aggregates is in a contrast with the weak interaction among molecularly dispersed PHIC chains.