Two or more macronuclear molecules encode histone H4 among eight stichotrichs (Sterkiella nova, Sterkiella histriomuscorum, Stylonychia mytilus, Stylonychia lemnae, Pleurotricha lanceolata, Oxytricha granulifera, Sterkiella sp. (Aspen), and Paraurostyla viridis). Only one macronuclear molecule encodes histone H4 in Uroleptus sp. Histone H4 molecules have been sequenced in five of the stichotrichs. Codon bias is extreme. The encoded amino acid sequences (104 amino acids) are identical. They differ significantly from the histone H4 sequences encoded by the hypotrichs, Euplotes aediculatus and Moneuplotes crassus (both 107 amino acids). Three major and five minor blocks of conserved nucleotide sequences are present throughout the ∼1150 bp 5′ noncoding leaders in the five stichotrichs. These conserved sequences may serve in regulation of gene function. However, all five 5′ leaders also contain different ORFs encoding amino acid sequence with similarity to sequences in GenBank. Except possibly for the ORF in Stylonychia mytilus and an ORF in Pleurotricha lanceolata, the ORFs appear not to be significant. The 50 bp in the ends of the macronuclear molecules contain an anomalous base composition that may be important in genome processing. The micronuclear histone H4 gene in Sterkiella nova contains an IES in the 5 leader, and the ORF in Sterkiella histriomuscorum contains a single IES.