The solubilities of phenylphosphinic acid from (297.79 to 312.84) K, hydroxymethylphenylphosphinic acid from (307.45 to 357.11) K, p-methoxyphenylphosphinic acid from (303.35 to 337.35) K, and p-methoxyphenylhydroxy-methylphosphinic acid from (303.95 to 346.45) K in water were measured. The concentration of the solution was determined by titration with sodium hydroxide using phenolphthalein as the indicator. The solubilities of triphenylphosphine from (299.65 to 327.15) K in methanol and from (297.45 to 327.65) K in ethanol, tri(p-methoxyphenyl)phosphine from (293.35 to 322.65) K in methanol and from (298.25 to 328.15) K in ethanol, and tri(p-methoxyphenyl)phosphine oxide from (299.15 to 337.65) K in cyclohexane were determined using a dynamic method. The estimated uncertainty of all the solubility values based on error analysis and repeated observations was within 2.3 %.